Eukaryotic 18S rRNA Endogenous Control (VIC™/TAMRA™ probe, primer limited) - FAQs

3 个常见问题解答

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.

How can I calculate the concentration of a TaqMan probe?

The initial concentration or total yield of your synthesized probe is listed on the data sheet supplied with the probe. TaqMan probes are sometimes shipped in the lyophilized state, but more often are shipped in solution (1X TE). To create a working stock solution of your probe or primers, you should reconstitute or dilute the probe in the appropriate volume of sterile 1X TE (1 mM Tris, 0.1 mM EDTA, pH 8.0) or sterile, nuclease-free H2O. Detailed instructions on how to calculate the proper volume of solution to add to your probe are provided in our online Tutorial document "Reconstituting and Diluting Primers and TaqMan Probes". You can find a copy on our website by entering this title in the main Search field.

Why does a TaqMan TAMRA probe need to have more C's (Cytosines) than G's (Guanidines) in the sequence?

Empirical data has shown that TaqMan TAMRA probes which contain more Gs than Cs will generally have lower ΔRn values and overall poor performance compared to those that do not. For more information on designing TaqMan TAMRA probes, please consult tutorials related to the Primer Express software.