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General

We offer the BrainStain™ Imaging Kit (Cat. No. B34650) for staining brain cryosections. This kit enables three-color labeling of myelin, neurons, and nuclei in brain cryosections in a single 20-minute staining step.

The solid and crystalline forms of DiI and other related dyes (Cat. Nos. D282, D3911, D7757, and D12731) are sometimes placed in contact with a specific neuron where it will travel down the cell by lateral diffusion via the membrane. Alternatively, our NeuroTrace™ Tissue Labeling Paste can be scooped onto a needle and placed onto particular neurons.

Please see the table below for a comparison of our neuronal cell labeling methods.

Product

Method of labeling

Labeling intensity

Features

Neuron-specific antibodies

Primary antibodies directed to proteins expressed in neuronal cells.

Proportional to the amount of protein expressed.

Provides the only neuronal specific labeling method. 

Lipophilic neuronal yracers

Hydrophobic dyes are incorporated into lipids in the cell.

This labeling method provides the most intense labeling because of the abundant amount of lipids.

Allows tracing of neurons throughout the sample.

Fluorescently labeled dextrans

Normally dextrans are microinjected.

Labeling can be intense since all the cytoplasm can be labeled.

Allows labeling of a single neuron avoiding fluorescent background.

Membrane potential indicators

Dyes are loaded into live cells in aqueous buffers.

Depends on either changes in structure due to the electrical field they are in, or dye influx due to depolarization.

Changes in membrane potential play a central role in physiological processes, including nerve-impulse propagation, muscle contraction, and cell signaling.

Factors to consider are size of tracer, method of delivery (injection, direct application to tissue, etc.), and if the tracer needs to be fixable. Here are some links to details about the various classes of neuronal tracers we offer and how to choose between them:

Neuronal Specific Antibodies

Please note that only antibodies against neuronal proteins are specific to neuronal cells. We carry antibodies to GFAP, HuC/HuD, NMDA receptor, synapsin I as well as many other antibodies for neuronal proteins. More information and a link to our primary antibody search tool can be found below:

Lipophilic Neuronal Tracers

Select the dye that is compatible with your available excitation source(s) and emission filter set/channels. The solid, paste and crystal forms can be applied directly to neurons in tissues. For labeling cells in culture or microinjection, the lipophilic dyes in solution or solid form can be used.

The transport is fairly slow, around 6 mm/day in live tissue and slower in fixed tissue, so diffusion of lipophilic carbocyanine tracers from the point of their application to the terminus of a neuron can take several days to weeks The FAST DiO and DiI analogs (which have unsaturated alkyl tails) can improve transport rate by around 50%. 

Dextran Neuronal Tracers

The NeuroTrace™ BDA-10,000 Neuronal Tracer Kit (Cat. No. N7167) manual has a good protocol for injection procedures and neuronal tracing using the10,000 MW lysine-fixable biotin dextran amine (BDA). This protocol could potentially be applied to other fluorescent dextrans.

Please review Tables 1a and 1b on pages 4 and 5.

Dextrans with molecular weights from 3,000 to 70,000 have been used, however the 3,000 and 10,000 MW dextrans are most commonly used for neuronal tracing. The 3,000 MW dextrans are used for more detailed tracing of fine neuronal projections, investigating gap junctions, and diffuse more quickly; while the 10,000 MW dextrans have slower distribution, longer cellular retention, and do not cross gap junctions.

We do not determine the net charge of the dextran conjugates. The net charge depends on the fluorophore used to label the dextran and the method of preparing the conjugate. We label some dextrans as neutral or anionic based on the fluorophore used, however the net charge of the dextran may not always be the same as the dye. The Alexa Fluor™, Cascade Blue™, Lucifer Yellow, fluorescein, and Oregon Green™ dextrans are intrinsically anionic, whereas most of the dextrans labeled with the zwitterionic Rhodamine B, tetramethylrhodamine and Texas Red™ dyes are essentially neutral.

Polar Neuronal Tracers

Lucifer Yellow CH is a hydrazide, so any of our Alexa Fluor™ or fluorescent hydrazides could potentially be used. A listing of them can be found here.

Wheat germ agglutinin and cholera toxin conjugates have been used for retrograde tracing. They may have some anterograde tracing in some applications. A selection guide can be found here.

Membrane Potential Indicators

Molecules that change their structure in response to the surrounding electric field can function as fast-response probes for the detection of transient (millisecond) potential changes. Slow-response dyes function by entering depolarized cells and binding to proteins or membranes. Increased depolarization results in additional dye influx and an increase in fluorescence, while hyperpolarization is indicated by a decrease in fluorescence. Fast-response probes are commonly used to image electrical activity from intact heart tissues or measure membrane potential changes in response to pharmacological stimuli. Slow-responding probes are often used to explore mitochondrial function and cell viability.

Neuronal Fluorescent Imaging Reagents

The dyes are proprietary, however they are stains that label the Nissl substance, which is composed of ribosomal RNA associated with the rough endoplasmic reticulum and is present in high amounts in neuronal cells. 

We have only tested them on mouse brain cryosections, however there are citations describing their use on paraffin tissue sections. 

They are proprietary lipid stains that stain myelin, but are not neuron specific.

We have only tested them on mouse brain cryosections. 

We have only tested them on mouse brain cryosections. They might work on neurons in culture, but would likely stain the membrane and there would be some endocytosis of the stains. Myelin sheaths may show enhanced intensity.

The BrainStain™ Imaging Kit enables three-color staining of myelin, neurons, and nuclei in brain cryosections in a single 20-minute staining step. It includes FluoroMyelin™ Green dye, NeuroTrace™ 530/615 red fluorescent Nissl stain, and DAPI for staining nuclei.

Neuronal Health

PrestoBlue™ Cell Viability Stain and CyQUANT™ Cell Proliferation Assay Kit can be used. We also offer a Neurite Outgrowth Staining Kit (Cat. No. A15001). More information about our different assays for neuronal cell health can be found here.

No, the viability dye and membrane stain can stain any cell type. Other Neurite Outgrowth Staining Kit FAQs can be found here.