The easy to use Thermo Scientific™ Multidrop™ Microplate Dispensers family provides unrivalled levels of performance to meet all requirements for reagent dispensing, offering high-speed, continuous dispensing with outstanding flexibility, precision, and accuracy. Multidrop dispensers feature a detachable autoclavable cassette for dispensing reagents, diluents, cells, and beads.

Reagent atlas

Example of reagents dispensed with Multidrops:

Organic SolventsDetails & Comments
Acetic acid 
Acetone 
Acetonitirile 
DMSO, dimethyl sulfoxide 
Ethanol 
Isopropanol 
Viscose SolutionsDetails & Comments
10% Glycerol 
BuffersDetails & Comments
0.1% Brij35 bufferAdjust dispensing speed. Medium speed recommended for best CV (Multidrop Combi)
20% Tris base 
145 mM HEPES, 0.1% NaCl 
100 mM sodium phosphate w/ BSA for enzyme 
IMAP detection reagentSmall tube plastic tip dispensing cassette
IMAP 1x kinase bufferSmall tube metal tip dispensing cassette
Hanks Hepes, cells. Cis HTRF kitSmall tube metal tip dispensing cassette
PCR mixture 
50nM HEPES, 10% glycerol, 0.1 % BSA 
TempliPhi reagent 
PBS buffer 
Tris buffer 
Growth MediaDetails & Comments
M3 media with and without 10% FCS 
Schneider medium with 10% FBSUse plastic tip cassette. Medium dispensing speed. Avoid backflush due to frothing.
DMEM with 10% FCS 
Kaighn's media with 10% FBS 
BeadsDetails & Comments
Polystyrene beadsSmall tube metal tip dispensing cassette tested. Test volume 5µl volune (100 mg/ml)
Yittrium oxide beadsPrime/empty between each plate. Larger prime volume. Medium speed. Small tube metal tip dispensing cassette tested.Test volume 10µl volume (5-20 mg/ml)
Tetra ethylene glycol carboxylated beads (0.8µm) 
Alpha screen beads 
Protein SolutionDetails & Comments
0.1% BSAMedium dispensing speed recommended for best CV
Plasma 
AgarPreheat tubing with warm water. (55C). Dispense warm water after 10-15 plates to clean the tips, prime and continue. Clean immediately after dispensing with warm water.
  

Note: The data presented here are based on available information regarding material compatibility and can be considered as general guidelines for product use. In many cases it is imperative that practical tests be carried out to confirm compatibility.

General instructions for cell dispensing

The capability to dispense viable cells requires gentle handling. This requirement is fulfilled with the Multidrop dispensers using either a standard or small tube dispensing cassette.

The most important thing when cell dispensing is to ensure the cells stay in a homogenous solution, which is achieved by constant mixing. This ensures that cells flow evenly in the tubing and can be dispensed with high precision. The main requirements for successful dispensing of different cell lines are similar; the practical issues are described in the following document: Maintenance guide for cell dispensing with Thermo Scientific Multidrop Combi.

Cell lines

Adherent cells require a surface for growth and differentiation. These cells need first to be detached with either trypsin-EDTA or an enzyme mix. After the detachment and washing steps and to guarantee the best dispensing result, it is essential to take care that the cells are evenly distributed in the liquid and no clumps are formed.

Non-adherent cell lines grow in suspension and require no surface for survival. Typical examples of these are blood cells, insect cells, and some plant cells. The same rules apply to dispensing of these cells. Ensuring effective and gentle mixing is still the main issue for successful dispensing.

• CHO cells

• Drosophila S2R+ cells

• Lymphoblastoid cells

• Drosophila Kc167 cells

• HeLa cells

• Fischer rat thyroid (FRT) epithelial cells

• HEK 293 cells

• Clonetics human neural progenitor cells

• Colon carcinoma cells (HCT116, HT29)

• Human ovarian epithelial cancer (OSKOV3)

• Primary human white blood cells

• Human lung epithelial cancer (A549)

• Cell lung carcinoma cells (A549)

• Human central nervous system epithelial cancer (SF268)

• Human astrocytoma cell line (U373)

• WSS-1 cell line

• Human colorectal cells HCT116

• Mouse hippocampal cells (HT-22)

Microbes

Examples of cells successfully dispensed:

  • Staphylococcus aureus bacteria 

Other

Examples of cells successfully dispensed:

  • Primary cells isolated from Drosophila embryos
  • Fungi
  • Drosophila gastrula stage embryos

If you would like to share information about your cell dispensing experiment with others, please contact us using contact details provided in the Ask & Share section.

Related publications

Cell Lines
• Choy et al. (2008). Genetic Analysis of Human Traits in Vitro: Drug Response and Gene Expression in Lymphoblastoid Cell Lines. PLoS Genetics 4 (11).
• Eggert et al. (2004). Parallel Chemical Genetic and Genome-Wide RNAi Screens Identify Cytokinesis Inhibitors and Targets. PloS Biology 2 (12): e379.
• Gopalakrisshnan el al. (2005). An Offline-Addition Format for Identifying GPCR Modulators by Screening 384-Well Mixed Compounds in the FLIPR. J Biomol Screen 10:46.
• Hardcastle et al. (2007). A Duplexed Phenotypic Screen for the Simultaneous Detection of Inhibitors of the Molecular Chaperone Heat Shock Protein 90 and Modulators of Cellular Acetylation. Mol Cancer Ther 6(3): 1112–22.
• Iourgenko et al. (2003). Identification of a Family of cAMP Response Element-Binding Protein Coactivators by Genome-Scale Functional Analysis in Mammalian Cells. Proc Natl Acad Sci  100(21): 12147–12152.
• Kiger et al. (2003). A Functional Genomic Analysis of Cell Morphology Using RNA Interference. J  Biol  2(27).
• Lundholt et al. (2003). A Simple Technique for Reducing Edge Effect in Cell-Based Assays. J Biomol Screen 8(566).
• Muller et al. (2005). Identification of JAK/STAT signalling components by genome-wide RNA interference. Nature 436(11).
• Pedemonte et al. (2005). Phenylglycine and Sulfonamide Correctors of Defective _F508 and G551D Cystic Fibrosis Transmembrane Conductance Regulator Chloride-Channel Gating. Mol Pharmacol  67(5).
• Richards et al. (2006). High Content Screening: A Powerful Approach to Systems Cell Biology and Drug Discovery. In: Methods in Molecular Biology  vol 356: Humana Press, Inc., Totowa, NJ.
• Sun et al. (2006). Chronic Inhibition of Cardiac Kir2.1 and hERG Potassium Channels by Celastrol with Dual Effects on Both Ion Conductivity and Protein Trafficking. J  Biol Chem 281(9):5877-5884.
• Tanaka et al. (2005). An Unbiased Cell Morphology–Based Screen for New, Biologically Active Small Molecules. PloS Biol  3(5): e128.
• Titus et al. (2008). Quantitative High-Throughput Screening Using a Live-Cell cAMP Assay Identifies Small-Molecule Agonists of the TSH Receptor. J Biomol Screen 13(120).
• Weber et al. (2004). A 1,536-Well cAMP Assay for Gs- and Gi-Coupled Receptors Using Enzyme Fragmentation Complementation. Assay Drug Dev Technol  2(1).
• Weimin Tang and Mary Jo Wildey (2004). Development of a Colorimetric Method for Functional Chloride Channel Assay. J Biomol Screen 9(607).
• Zitzler et al. (2004). High-Throughput Functional GenomicsIdentifies Genes That Ameliorate Toxicity Due to Oxidative Stress in Neuronal HT-22 Cells. Mol Cell Proteomics 3:834–840

Microbes
• Sandberg et al. (2008). Automating a 96-well Microtiter Plate Model for Staphylococcus aureus Biofilms: An Approach to Screening of Natural Antimicrobial Compounds. Intl J Antimicro Ag 32:233–240.

Other
• Bai et al. (2008). RNA Interference Screening in Drosophila Primary Cells for Genes Involved in Muscle Assembly and Maintenance. Development 135: 1439-1449.
• Bills et al.(2007). Enhancement of Antibiotic and Secondary Metabolite Detection from Filamentous Fungi by Growth on Nutritional Arrays. J Appl Microbiol  ISSN 1364 – 5072.
• Sepp et al. (2008). Identification of Neural Outgrowth Genes Using Genome-Wide RNAi. PloS Genetics 4(7). 

Routine Maintenance - Instrument

  • For a reliable daily operation, keep the instrument free of dust and liquid spills.
  • Clean the outside of the instrument periodically with a cloth dampened with water, a mild detergent or 70% ethanol when necessary.
  • Immediately wipe away spilt saline solutions, solvents, acids or alkaline solutions from outer surfaces to prevent damage.
  • Abrasive cleaning agents are not recommended because they are likely to damage the plastic instrument cover.
  • Do not expose the surfaces to concentrated acids or concentrated alcohols for prolonged periods of time as damage may occur.
  • If any surfaces are contaminated with biohazardous material, a mild sterilizing solution should be used. Ensure that the bottom of each microplate is dry. Fluid on the bottom of a microplate may present a contamination hazard.
  • Example of decontaminants:

    • Ethanol 70%
    Virkon solution 1 - 3%
    Glutaraldehyde solution 4%
    Chloramine T
    Microcide SQ 1:64

Note! If you want to include ethanol wash make sure sure you always wash first with ddH20. Ethanol will precipitate remaining proteins.

Dispensing cassette maintenance: Multidrop Combi, Multidrop 384, Multidrop DW
Handle the dispensing cassette with great care so that you do not damage the tubes and dispensing tips. These factors affect the useful life of the dispensing cassette.

Daily Maintenance
Cleaning the dispensing cassette after use: 

  1. Wash the tubes by predispensing them with ddH2O. Make sure all the tubes are washed properly.
    • Standard tube dispensing cassette: use min. 20ml ddH2O for washing.
    • Small tube dispensing cassette: use min. 10ml ddH2O for washing.
    • If cleaning with water is insufficient, use a mild laboratory detergent (for example, TWEEN®-20 or TritonTM X-100) or a cleaning solution (e.g. 1% Micro-90® Cleaning Solution by Cole-Parmer) and then predispense with large amounts of ddH2O.
  2. Empty the tubings of the dispensing cassette. The dispensing cassette can be dried at room temperature.
  3. After washing, store the dispensing cassette in the rest position.

Caution! When dispensing proteins, wash first with ddH2O before ethanol to avoid precipitation.

Regular Maintenance

  • Avoid dust or any particles > 50 µm when operating with the dispensing cassette.
  • Calibrate the dispensing cassette at least once a month.
  • For small tube cassettes, it is recommended to filter the reagents to avoid any clogging. Especially all dye solutions should be filtered for the dispensing.

Cleaning plastic/metal tips:

  1. Press the EMPTY button for a few seconds. Then press the PRIME button for a few seconds.
  2. Place a liquid reservoir filled with ddH2O under the cassette tips so that the tips are submerged in liquid, and press the EMPTY button.
  3. The small plastic tip is very fragile, be careful.

Caution! To avoid particles re-entering the reagent, place the tubing end weight into a separate vessel while you empty the tubing.

Cleaning the metal tips:

  1. Open the cassette cover and detach the tubing from the tips and remove the tip holder from the cassette.    
  2. Attach the syringe with the filter unit and press ddH2O, ethanol or another suitable liquid through the syringe to wash out any particles from the tubing.    
  3. Attach the short tubing onto the outlet of the tip, and press liquid through the syringe.    
  4. Verify the cleaning, and insert the tubing back onto the tips, and place the tip holder back into the cassette.

For more detailed instructions of cleaning the metal tips, please see the Multidrop Combi user manual.

Trouble Shooting

  1. If the tip(s) are clogged or dripping, you can first try to clean the tips according to the regular maintenance instructions above to remove the blockage or prime and empty the tubing several times with a mild detergent and rinse properly with ddH2O.
  2. The dispensing cassette should be stored in the rest position. Recalibrate the cassette if the tubing has been under tension for a prolonged period.
  3. Wet outer surface of the tip(s) may form disturbing droplets.
  4. After autoclaving, the dispensing cassette must cool down at least two hours to room temperature before use.

General instructions for cell dispensing

Daily Maintenance The basic maintenance procedure should be performed regularly and on a daily basis to ensure proper dispensing valve and tubing operation:    

  1. Filter all reagents, detergents, solutions and water before use to remove solid particles.    
  2. Rinse the tubings with distilled and filtered laboratory-grade water always after using the instrument.    
  3. Before a prolonged standby, wash the tubings with 70% ethanol, and run the tubings dry to avoid microbial growth from developing.

Regular Maintenance

To ensure trouble-free dispensing, do not touch the dispensing valves or the tubing inlet. If there is a reason to suspect that particles have entered the tubings, clean the tubings. Check the reagent filter weekly, wash it regularly and replace it when necessary. It is possible to clean the reagent filter with an ultrasonic cleaner.

Cleaning the valves and tubings:

First carry out the following backflush procedure:  

  • Empty the reagent reservoir or fit an empty reagent reservoir and remove the reagent filter at the bottom of the reagent reservoir by pulling it off by the end of the cap tube.  
  • Place a disposable reagent basin or a 96-well plate filled with 20-50ml of filtered detergent under the dispensing valves so that the liquid is in contact with the valves.  
  • Press the EMPTY button to rinse the valves and tubings.    
  • Place another disposable reagent basin or a 96-well plate filled with distilled and filtered laboratory-grade water under the dispensing valves so that the liquid is in contact with the valves.  
  • Press the EMPTY button to rinse the valves and tubings properly.

Trouble Shooting    

  • To remove persistent air bubbles from the hosing and microsolenoid dispensing valves, use a tip washing. The tip washing is started by pressing the TIP WASH button. The liquid comes in pulses and one liquid channel at a time to maintain a maximum flow through the dispensing valve.    
  • If the valve(s) are clogged or dripping, you can first try to clean the tips according to the regular maintenance instructions above to remove the blockage.  
  • The tip washing is possible to do before the dispensing.      
  • Clean the tubes and valves by emptying with the EMPTY button.    
  • Do not tighten the valve too much.      
  • There is one spare valve included.      
  • It is possible to remove the reagent filter.

In the laboratory

This section includes tips which can help your work with the Multidrops and give insights which are not readily available in the manual. In this section are included tips from our customers who have the greatest experience in their hands. If you have something you would like to share with others, please contact us using contact details provided in the Ask & Share section.

Multidrop Combi, Multidrop 384 and Multidrop DW
Cleaning procedures for dispensing cassettes:

"The dispensing cassette can be hooked up to a faucet that has a piece of tygon tubing attached that is wide enough to accommodate the end of the cassette with the tubing weight on the end. Then the water is just turned on. This eliminates tension due to the pump."

"The whole dispensing cassette can be placed directly into the sonication bath for cleaning."

"The tubings are often coated with the base buffer used for the assay to prevent sticking. For coating, for example, is used the 10 x buffer concentration."

Think also other components involved:
"We were dispensing with the Multidrop Combi into a 384-well plate and had weird discrepancy of results in odd-even rows. We were using the Tecan Safire 2 microplate reader in polarization mode.The Tecan representative suggested that we would introduce a delay of 300 msec in the measurement parameter menu, and that really eliminated the odd-even row discrepancy completely. (A delay of 100 msec worked just as well.) I assume that the problem is in the plate transport in the Safire2 microplate reader, which has differential effects on the liquid meniscus depending on whether the plate transport is towards left or right. But not knowing this, I could have sworn that the problem was due to the unequal filling of the rows by the Multidrop, the difference in the readings without the time delay being about 8%."

Multidrop Combi nL
"We had problems when we evaluated the accuracy values with the Artel MVS dye system. The dye is diluted in DMSO in this method, and once the dye is diluted in DMSO, the final solution is actually only 80% DMSO which is different enough from the 100% DMSO solution to affect the accuracy values. So, 80% DMSO should be used for calibrating the Multidrop Combi nL if this system is utilized."

Frequently Asked Questions

What cassettes are included in a new instrument?
Multidrop Combi includes three types of dispensing cassettes, Standard tube cassette (Cat. No. 24072670), Small tube metal tip dispensing cassette (Cat. No. 24073295) and Small tube plastic tip dispensing cassette (Cat. No. 24073290).

What is the lifetime for a dispensing cassette?
The lifetime for the standard dispensing cassette is 3000-5000 plates of 96-well plates with a 100µl volume, and for the small tube dispensing cassette 1000 plates of 384-well plates with a 5µl volume.

Can the dispensing cassette be autoclaved?
Yes, the standard tube cassette can be autoclaved 50 times and the small tube cassette 10 times at 1 bar pressure at 121°C for 20 minutes.

What is the diameter of the cassette tip?
The inner diameter of the tip is 0.5mm in the standard tube cassette, and 0.22mm in the small tube cassette.

What is the diameter of cassette tubing?
The diameter of the standard tubing is 1.3mm and diameter of the small tubing is 0.4mm.

What are the smallest increment volumes with the small and standard tube cassettes?
The smallest increment is 0.5µl for the small tube cassette and 5µl for the standard tube cassette.

How often should the dispensing cassette be calibrated?
It is recommended to calibrate at least once a month depending on the frequency of the use and the liquids used. The cassette should also be calibrated if it is left under tension for prolonged periods.

How should the dispensing cassette be maintained?
The cleaning procedure always depends on the reagents dispensed. Always wash first with plenty of distilled water. Then you can clean with mild a detergent solution, for example, tween, triton or a cleaning solution (for example, 1% Micro-90).

Then wash again with plenty of distilled water. If you plan to run EtOH through the dispensing cassette, make sure there are no remnants of other liquids since EtOH will effectively precipitate proteins. Please see maintenance for further instructions.

Can I save a dispensing protocol?
Yes, the use of the Multidrop Combi allows you to save at least 100 dispensing protocols. First you need to proceed into the Save/Edit row (the last row in theMain menu), press OK and then the right pointing arrow.

Enter the name for protocol by selecting the letters with the arrow keys and press OK to accept the name. The Protocol name appears in the last row in the Main menu.

Protocols are stored according to the plate type and you will find the protocol by first selecting the plate type, and then selecting it from the list.

What is the part number for re-ordering strip plates used for calibration?
You can use Nunc plates with the catalog number 473709.

I need to dispense a different volume into each well of the plate. How do I do that?
You can use the Multidrop Combi nL for that. First you need to select the volume for each well using FILLit Software. You can also copy/paste volumes into the plate layout.

The liquid is frothing during cell dispensing. How can that be minimized?
The cell culture media contains serum which can cause frothing. You can try lower dispensing speed, use lower mixing speed and use prime to empty to tubing to avoid excess foaming with empty function.

The tip of dispensing cassette was blocked during cell dispensing. What is recommended?
Use mild detergent or cleaning solution. You can let the detergent stand in the tubing 5-10 minutes to dissolve the clog. Then prime and empty by turns with the detergent and rinse well with several times with distilled water.

Ask & share

Offering high-speed, continuous dispensing with outstanding flexibility, precision and accuracy, Thermo Scientific Multidrop Microplate Dispensers are designed for ease of use, offering unrivalled levels of performance to meet all requirements fo reagent dispensing. Each Multidrop dispenser features a detachable autoclavable cassette for the dispensing of reagents, diluents, cells and beads.

You can send us tips you would like to share with others, info of your experiments or send us questions and comments into the following email address info.microplateinstruments@thermofisher.com. The best tips will be awarded.

For routine questions, product availability and pricing, please contact your local Thermo Fisher Scientific representative.

Reagent atlas

Reagent atlas

Example of reagents dispensed with Multidrops:

Organic SolventsDetails & Comments
Acetic acid 
Acetone 
Acetonitirile 
DMSO, dimethyl sulfoxide 
Ethanol 
Isopropanol 
Viscose SolutionsDetails & Comments
10% Glycerol 
BuffersDetails & Comments
0.1% Brij35 bufferAdjust dispensing speed. Medium speed recommended for best CV (Multidrop Combi)
20% Tris base 
145 mM HEPES, 0.1% NaCl 
100 mM sodium phosphate w/ BSA for enzyme 
IMAP detection reagentSmall tube plastic tip dispensing cassette
IMAP 1x kinase bufferSmall tube metal tip dispensing cassette
Hanks Hepes, cells. Cis HTRF kitSmall tube metal tip dispensing cassette
PCR mixture 
50nM HEPES, 10% glycerol, 0.1 % BSA 
TempliPhi reagent 
PBS buffer 
Tris buffer 
Growth MediaDetails & Comments
M3 media with and without 10% FCS 
Schneider medium with 10% FBSUse plastic tip cassette. Medium dispensing speed. Avoid backflush due to frothing.
DMEM with 10% FCS 
Kaighn's media with 10% FBS 
BeadsDetails & Comments
Polystyrene beadsSmall tube metal tip dispensing cassette tested. Test volume 5µl volune (100 mg/ml)
Yittrium oxide beadsPrime/empty between each plate. Larger prime volume. Medium speed. Small tube metal tip dispensing cassette tested.Test volume 10µl volume (5-20 mg/ml)
Tetra ethylene glycol carboxylated beads (0.8µm) 
Alpha screen beads 
Protein SolutionDetails & Comments
0.1% BSAMedium dispensing speed recommended for best CV
Plasma 
AgarPreheat tubing with warm water. (55C). Dispense warm water after 10-15 plates to clean the tips, prime and continue. Clean immediately after dispensing with warm water.
  

Note: The data presented here are based on available information regarding material compatibility and can be considered as general guidelines for product use. In many cases it is imperative that practical tests be carried out to confirm compatibility.

Cell dispensing

General instructions for cell dispensing

The capability to dispense viable cells requires gentle handling. This requirement is fulfilled with the Multidrop dispensers using either a standard or small tube dispensing cassette.

The most important thing when cell dispensing is to ensure the cells stay in a homogenous solution, which is achieved by constant mixing. This ensures that cells flow evenly in the tubing and can be dispensed with high precision. The main requirements for successful dispensing of different cell lines are similar; the practical issues are described in the following document: Maintenance guide for cell dispensing with Thermo Scientific Multidrop Combi.

Cell lines

Adherent cells require a surface for growth and differentiation. These cells need first to be detached with either trypsin-EDTA or an enzyme mix. After the detachment and washing steps and to guarantee the best dispensing result, it is essential to take care that the cells are evenly distributed in the liquid and no clumps are formed.

Non-adherent cell lines grow in suspension and require no surface for survival. Typical examples of these are blood cells, insect cells, and some plant cells. The same rules apply to dispensing of these cells. Ensuring effective and gentle mixing is still the main issue for successful dispensing.

• CHO cells

• Drosophila S2R+ cells

• Lymphoblastoid cells

• Drosophila Kc167 cells

• HeLa cells

• Fischer rat thyroid (FRT) epithelial cells

• HEK 293 cells

• Clonetics human neural progenitor cells

• Colon carcinoma cells (HCT116, HT29)

• Human ovarian epithelial cancer (OSKOV3)

• Primary human white blood cells

• Human lung epithelial cancer (A549)

• Cell lung carcinoma cells (A549)

• Human central nervous system epithelial cancer (SF268)

• Human astrocytoma cell line (U373)

• WSS-1 cell line

• Human colorectal cells HCT116

• Mouse hippocampal cells (HT-22)

Microbes

Examples of cells successfully dispensed:

  • Staphylococcus aureus bacteria 

Other

Examples of cells successfully dispensed:

  • Primary cells isolated from Drosophila embryos
  • Fungi
  • Drosophila gastrula stage embryos

If you would like to share information about your cell dispensing experiment with others, please contact us using contact details provided in the Ask & Share section.

Related publications

Cell Lines
• Choy et al. (2008). Genetic Analysis of Human Traits in Vitro: Drug Response and Gene Expression in Lymphoblastoid Cell Lines. PLoS Genetics 4 (11).
• Eggert et al. (2004). Parallel Chemical Genetic and Genome-Wide RNAi Screens Identify Cytokinesis Inhibitors and Targets. PloS Biology 2 (12): e379.
• Gopalakrisshnan el al. (2005). An Offline-Addition Format for Identifying GPCR Modulators by Screening 384-Well Mixed Compounds in the FLIPR. J Biomol Screen 10:46.
• Hardcastle et al. (2007). A Duplexed Phenotypic Screen for the Simultaneous Detection of Inhibitors of the Molecular Chaperone Heat Shock Protein 90 and Modulators of Cellular Acetylation. Mol Cancer Ther 6(3): 1112–22.
• Iourgenko et al. (2003). Identification of a Family of cAMP Response Element-Binding Protein Coactivators by Genome-Scale Functional Analysis in Mammalian Cells. Proc Natl Acad Sci  100(21): 12147–12152.
• Kiger et al. (2003). A Functional Genomic Analysis of Cell Morphology Using RNA Interference. J  Biol  2(27).
• Lundholt et al. (2003). A Simple Technique for Reducing Edge Effect in Cell-Based Assays. J Biomol Screen 8(566).
• Muller et al. (2005). Identification of JAK/STAT signalling components by genome-wide RNA interference. Nature 436(11).
• Pedemonte et al. (2005). Phenylglycine and Sulfonamide Correctors of Defective _F508 and G551D Cystic Fibrosis Transmembrane Conductance Regulator Chloride-Channel Gating. Mol Pharmacol  67(5).
• Richards et al. (2006). High Content Screening: A Powerful Approach to Systems Cell Biology and Drug Discovery. In: Methods in Molecular Biology  vol 356: Humana Press, Inc., Totowa, NJ.
• Sun et al. (2006). Chronic Inhibition of Cardiac Kir2.1 and hERG Potassium Channels by Celastrol with Dual Effects on Both Ion Conductivity and Protein Trafficking. J  Biol Chem 281(9):5877-5884.
• Tanaka et al. (2005). An Unbiased Cell Morphology–Based Screen for New, Biologically Active Small Molecules. PloS Biol  3(5): e128.
• Titus et al. (2008). Quantitative High-Throughput Screening Using a Live-Cell cAMP Assay Identifies Small-Molecule Agonists of the TSH Receptor. J Biomol Screen 13(120).
• Weber et al. (2004). A 1,536-Well cAMP Assay for Gs- and Gi-Coupled Receptors Using Enzyme Fragmentation Complementation. Assay Drug Dev Technol  2(1).
• Weimin Tang and Mary Jo Wildey (2004). Development of a Colorimetric Method for Functional Chloride Channel Assay. J Biomol Screen 9(607).
• Zitzler et al. (2004). High-Throughput Functional GenomicsIdentifies Genes That Ameliorate Toxicity Due to Oxidative Stress in Neuronal HT-22 Cells. Mol Cell Proteomics 3:834–840

Microbes
• Sandberg et al. (2008). Automating a 96-well Microtiter Plate Model for Staphylococcus aureus Biofilms: An Approach to Screening of Natural Antimicrobial Compounds. Intl J Antimicro Ag 32:233–240.

Other
• Bai et al. (2008). RNA Interference Screening in Drosophila Primary Cells for Genes Involved in Muscle Assembly and Maintenance. Development 135: 1439-1449.
• Bills et al.(2007). Enhancement of Antibiotic and Secondary Metabolite Detection from Filamentous Fungi by Growth on Nutritional Arrays. J Appl Microbiol  ISSN 1364 – 5072.
• Sepp et al. (2008). Identification of Neural Outgrowth Genes Using Genome-Wide RNAi. PloS Genetics 4(7). 

Maintenance

Routine Maintenance - Instrument

  • For a reliable daily operation, keep the instrument free of dust and liquid spills.
  • Clean the outside of the instrument periodically with a cloth dampened with water, a mild detergent or 70% ethanol when necessary.
  • Immediately wipe away spilt saline solutions, solvents, acids or alkaline solutions from outer surfaces to prevent damage.
  • Abrasive cleaning agents are not recommended because they are likely to damage the plastic instrument cover.
  • Do not expose the surfaces to concentrated acids or concentrated alcohols for prolonged periods of time as damage may occur.
  • If any surfaces are contaminated with biohazardous material, a mild sterilizing solution should be used. Ensure that the bottom of each microplate is dry. Fluid on the bottom of a microplate may present a contamination hazard.
  • Example of decontaminants:

    • Ethanol 70%
    Virkon solution 1 - 3%
    Glutaraldehyde solution 4%
    Chloramine T
    Microcide SQ 1:64

Note! If you want to include ethanol wash make sure sure you always wash first with ddH20. Ethanol will precipitate remaining proteins.

Dispensing cassette maintenance: Multidrop Combi, Multidrop 384, Multidrop DW
Handle the dispensing cassette with great care so that you do not damage the tubes and dispensing tips. These factors affect the useful life of the dispensing cassette.

Daily Maintenance
Cleaning the dispensing cassette after use: 

  1. Wash the tubes by predispensing them with ddH2O. Make sure all the tubes are washed properly.
    • Standard tube dispensing cassette: use min. 20ml ddH2O for washing.
    • Small tube dispensing cassette: use min. 10ml ddH2O for washing.
    • If cleaning with water is insufficient, use a mild laboratory detergent (for example, TWEEN®-20 or TritonTM X-100) or a cleaning solution (e.g. 1% Micro-90® Cleaning Solution by Cole-Parmer) and then predispense with large amounts of ddH2O.
  2. Empty the tubings of the dispensing cassette. The dispensing cassette can be dried at room temperature.
  3. After washing, store the dispensing cassette in the rest position.

Caution! When dispensing proteins, wash first with ddH2O before ethanol to avoid precipitation.

Regular Maintenance

  • Avoid dust or any particles > 50 µm when operating with the dispensing cassette.
  • Calibrate the dispensing cassette at least once a month.
  • For small tube cassettes, it is recommended to filter the reagents to avoid any clogging. Especially all dye solutions should be filtered for the dispensing.

Cleaning plastic/metal tips:

  1. Press the EMPTY button for a few seconds. Then press the PRIME button for a few seconds.
  2. Place a liquid reservoir filled with ddH2O under the cassette tips so that the tips are submerged in liquid, and press the EMPTY button.
  3. The small plastic tip is very fragile, be careful.

Caution! To avoid particles re-entering the reagent, place the tubing end weight into a separate vessel while you empty the tubing.

Cleaning the metal tips:

  1. Open the cassette cover and detach the tubing from the tips and remove the tip holder from the cassette.    
  2. Attach the syringe with the filter unit and press ddH2O, ethanol or another suitable liquid through the syringe to wash out any particles from the tubing.    
  3. Attach the short tubing onto the outlet of the tip, and press liquid through the syringe.    
  4. Verify the cleaning, and insert the tubing back onto the tips, and place the tip holder back into the cassette.

For more detailed instructions of cleaning the metal tips, please see the Multidrop Combi user manual.

Trouble Shooting

  1. If the tip(s) are clogged or dripping, you can first try to clean the tips according to the regular maintenance instructions above to remove the blockage or prime and empty the tubing several times with a mild detergent and rinse properly with ddH2O.
  2. The dispensing cassette should be stored in the rest position. Recalibrate the cassette if the tubing has been under tension for a prolonged period.
  3. Wet outer surface of the tip(s) may form disturbing droplets.
  4. After autoclaving, the dispensing cassette must cool down at least two hours to room temperature before use.

General instructions for cell dispensing

Daily Maintenance The basic maintenance procedure should be performed regularly and on a daily basis to ensure proper dispensing valve and tubing operation:    

  1. Filter all reagents, detergents, solutions and water before use to remove solid particles.    
  2. Rinse the tubings with distilled and filtered laboratory-grade water always after using the instrument.    
  3. Before a prolonged standby, wash the tubings with 70% ethanol, and run the tubings dry to avoid microbial growth from developing.

Regular Maintenance

To ensure trouble-free dispensing, do not touch the dispensing valves or the tubing inlet. If there is a reason to suspect that particles have entered the tubings, clean the tubings. Check the reagent filter weekly, wash it regularly and replace it when necessary. It is possible to clean the reagent filter with an ultrasonic cleaner.

Cleaning the valves and tubings:

First carry out the following backflush procedure:  

  • Empty the reagent reservoir or fit an empty reagent reservoir and remove the reagent filter at the bottom of the reagent reservoir by pulling it off by the end of the cap tube.  
  • Place a disposable reagent basin or a 96-well plate filled with 20-50ml of filtered detergent under the dispensing valves so that the liquid is in contact with the valves.  
  • Press the EMPTY button to rinse the valves and tubings.    
  • Place another disposable reagent basin or a 96-well plate filled with distilled and filtered laboratory-grade water under the dispensing valves so that the liquid is in contact with the valves.  
  • Press the EMPTY button to rinse the valves and tubings properly.

Trouble Shooting    

  • To remove persistent air bubbles from the hosing and microsolenoid dispensing valves, use a tip washing. The tip washing is started by pressing the TIP WASH button. The liquid comes in pulses and one liquid channel at a time to maintain a maximum flow through the dispensing valve.    
  • If the valve(s) are clogged or dripping, you can first try to clean the tips according to the regular maintenance instructions above to remove the blockage.  
  • The tip washing is possible to do before the dispensing.      
  • Clean the tubes and valves by emptying with the EMPTY button.    
  • Do not tighten the valve too much.      
  • There is one spare valve included.      
  • It is possible to remove the reagent filter.
In the laboratory

In the laboratory

This section includes tips which can help your work with the Multidrops and give insights which are not readily available in the manual. In this section are included tips from our customers who have the greatest experience in their hands. If you have something you would like to share with others, please contact us using contact details provided in the Ask & Share section.

Multidrop Combi, Multidrop 384 and Multidrop DW
Cleaning procedures for dispensing cassettes:

"The dispensing cassette can be hooked up to a faucet that has a piece of tygon tubing attached that is wide enough to accommodate the end of the cassette with the tubing weight on the end. Then the water is just turned on. This eliminates tension due to the pump."

"The whole dispensing cassette can be placed directly into the sonication bath for cleaning."

"The tubings are often coated with the base buffer used for the assay to prevent sticking. For coating, for example, is used the 10 x buffer concentration."

Think also other components involved:
"We were dispensing with the Multidrop Combi into a 384-well plate and had weird discrepancy of results in odd-even rows. We were using the Tecan Safire 2 microplate reader in polarization mode.The Tecan representative suggested that we would introduce a delay of 300 msec in the measurement parameter menu, and that really eliminated the odd-even row discrepancy completely. (A delay of 100 msec worked just as well.) I assume that the problem is in the plate transport in the Safire2 microplate reader, which has differential effects on the liquid meniscus depending on whether the plate transport is towards left or right. But not knowing this, I could have sworn that the problem was due to the unequal filling of the rows by the Multidrop, the difference in the readings without the time delay being about 8%."

Multidrop Combi nL
"We had problems when we evaluated the accuracy values with the Artel MVS dye system. The dye is diluted in DMSO in this method, and once the dye is diluted in DMSO, the final solution is actually only 80% DMSO which is different enough from the 100% DMSO solution to affect the accuracy values. So, 80% DMSO should be used for calibrating the Multidrop Combi nL if this system is utilized."

FAQs

Frequently Asked Questions

What cassettes are included in a new instrument?
Multidrop Combi includes three types of dispensing cassettes, Standard tube cassette (Cat. No. 24072670), Small tube metal tip dispensing cassette (Cat. No. 24073295) and Small tube plastic tip dispensing cassette (Cat. No. 24073290).

What is the lifetime for a dispensing cassette?
The lifetime for the standard dispensing cassette is 3000-5000 plates of 96-well plates with a 100µl volume, and for the small tube dispensing cassette 1000 plates of 384-well plates with a 5µl volume.

Can the dispensing cassette be autoclaved?
Yes, the standard tube cassette can be autoclaved 50 times and the small tube cassette 10 times at 1 bar pressure at 121°C for 20 minutes.

What is the diameter of the cassette tip?
The inner diameter of the tip is 0.5mm in the standard tube cassette, and 0.22mm in the small tube cassette.

What is the diameter of cassette tubing?
The diameter of the standard tubing is 1.3mm and diameter of the small tubing is 0.4mm.

What are the smallest increment volumes with the small and standard tube cassettes?
The smallest increment is 0.5µl for the small tube cassette and 5µl for the standard tube cassette.

How often should the dispensing cassette be calibrated?
It is recommended to calibrate at least once a month depending on the frequency of the use and the liquids used. The cassette should also be calibrated if it is left under tension for prolonged periods.

How should the dispensing cassette be maintained?
The cleaning procedure always depends on the reagents dispensed. Always wash first with plenty of distilled water. Then you can clean with mild a detergent solution, for example, tween, triton or a cleaning solution (for example, 1% Micro-90).

Then wash again with plenty of distilled water. If you plan to run EtOH through the dispensing cassette, make sure there are no remnants of other liquids since EtOH will effectively precipitate proteins. Please see maintenance for further instructions.

Can I save a dispensing protocol?
Yes, the use of the Multidrop Combi allows you to save at least 100 dispensing protocols. First you need to proceed into the Save/Edit row (the last row in theMain menu), press OK and then the right pointing arrow.

Enter the name for protocol by selecting the letters with the arrow keys and press OK to accept the name. The Protocol name appears in the last row in the Main menu.

Protocols are stored according to the plate type and you will find the protocol by first selecting the plate type, and then selecting it from the list.

What is the part number for re-ordering strip plates used for calibration?
You can use Nunc plates with the catalog number 473709.

I need to dispense a different volume into each well of the plate. How do I do that?
You can use the Multidrop Combi nL for that. First you need to select the volume for each well using FILLit Software. You can also copy/paste volumes into the plate layout.

The liquid is frothing during cell dispensing. How can that be minimized?
The cell culture media contains serum which can cause frothing. You can try lower dispensing speed, use lower mixing speed and use prime to empty to tubing to avoid excess foaming with empty function.

The tip of dispensing cassette was blocked during cell dispensing. What is recommended?
Use mild detergent or cleaning solution. You can let the detergent stand in the tubing 5-10 minutes to dissolve the clog. Then prime and empty by turns with the detergent and rinse well with several times with distilled water.

Ask and share

Ask & share

Offering high-speed, continuous dispensing with outstanding flexibility, precision and accuracy, Thermo Scientific Multidrop Microplate Dispensers are designed for ease of use, offering unrivalled levels of performance to meet all requirements fo reagent dispensing. Each Multidrop dispenser features a detachable autoclavable cassette for the dispensing of reagents, diluents, cells and beads.

You can send us tips you would like to share with others, info of your experiments or send us questions and comments into the following email address info.microplateinstruments@thermofisher.com. The best tips will be awarded.

For routine questions, product availability and pricing, please contact your local Thermo Fisher Scientific representative.