Distinguish true target negatives from PCR inhibition

Applied Biosystems TaqMan exogenous internal positive control reagents contain a pre-optimized internal positive control (IPC) with predesigned primers and a TaqMan probe. The IPC can be spiked into samples to distinguish true target negatives from PCR inhibition.

 

TaqMan exogenous internal positive control reagents allow you to simultaneously amplify the IPC and low-copy target DNA in the same tube. Although the target and IPC DNAs may differ in initial copy number, the concentration of the IPC primers in the PCR reaction is limiting, so that the amplification efficiency of the target reaction is not compromised.


Features

TaqMan exogenous IPC reagents are designed to:

Distinguish types of negative results

Distinguish between negative reactions from samples lacking the target sequence vs those containing a PCR inhibitor

Simultaneously amplify two DNAs

By labeling a low-copy target DNA with a FAM probe and the IPC with a VIC probe, the two can be amplified in the same tube

Prevent cross reactivity with target

Permits co-amplification of the IPC and the target sequence without compromising amplification of the target sequence  

Avoid amplification of endogenous genes

Maintains expression stability of the endogenous internal control or “housekeeping” gene


How it works

During amplification, the sample and IPC generate reporter fluorescence signals that help to identify unknown samples.

 

Positive and negative calls are made based on statistical analysis of data from the two dye layers. The statistical analysis sets up threshold values for positive FAM and VIC calls based on the No Template Control (NTC) and the Negative Internal Positive Control (IPC–) baselines.

 

In this kit, the FAM layer shows the positive (+) and negative (–) calls for the target template and the VIC layer shows the +/– calls for the IPC.

Interpreting negative results with TaqMan exogenous IPC reagents

 

If the detectable target template (FAM) call is …

And the detectable IPC (VIC) call is …

Then the target template is …

+

+ or –*

Present

+

Absent

No amp

 

*In the presence of a strong FAM signal for the target assay, a negative assignment and/or signal can be obtained in the VIC layer. This is a result of the limiting primer concentrations used in the IPC assay.


Ordering information