Can I multiplex my assays if my amplicons are not all the same length?
Yes, it is possible. The amplicons do not have to be the same length in order to duplex the assays. You need to use different reporter dyes on the probes in multiplex - they should have a substantial difference in maximum emission wavelength to be effective. A classic example is to use FAM and VIC for the 2 probes. Depending on the expression of the targets, you may also need to limit the primer concentration for one of the assays. This is common when duplexing a target and endogenous control (the control probe is VIC labeled and the primer concentration is decreased so the target assay can properly compete for use of enzyme and dNTPs).
I want to order a TaqMan Gene Expression Assay that you have discontinued. Is there a way do that?
Yes, you can order it as a custom assay. Since the assay is discontinued, it can not be ordered on-line. You will have to call or email the order to genomics@appliedbiosystems.com, and include the assay ID. The assay will be synthesized once the order is received. It will be designed and priced as a Custom TaqMan Gene Expression Assay so you will need to choose the scale.
Can I use TaqMan Gene Expression Assays for a gene copy number study?
TaqMan Gene Expression Assays with “_s1” as assay ID suffix are the assays whose primers and probes are designed within a single exon, and therefore, will detect genomic DNA. However, the application of these assays in gene copy number studies has not been validated. Other gene expression assays will not detect gDNA, let alone the region of variance.
I am working on both mouse and human samples for gene expression studies. Do you have one endogenous control that I can use with both species?
The 18S rRNA is highly conserved among eukaryotes. We have several configurations of assays for this gene: P/N 4331182, Assay ID: Hs99999901_s1; PN 4319413E, 4310893E, 4333760T, 4333760F, 4308329. You can use any of these for both human and mouse samples, as well as samples from any other eukaryotic species.
Can I check the end product of a TaqMan Gene Expression Assay by running an agarose gel?
Yes, you can check the end product on an agarose gel. If you use the TaqMan Universal PCR Master Mix (including AmpErase UNG, Cat. No. 4304437), we recommend running the gel immediately after the PCR, since the trace amount of AmpErase UNG may digest the end product that contains double-stranded DNA with dUTP incorporated. The average length of amplicon ranges from 50-150 bp. The exact amplicon length is indicated on the detailed page of each assay on our website. You can get to that page by clicking on the Assay ID; the amplicon information is listed in the section "Assay Details".