Eukaryotic 18S rRNA Endogenous Control (FAM™/MGB probe, non-primer limited), 125 Reactions - FAQs

查看更多产品信息 Eukaryotic 18S rRNA Endogenous Control (FAM™/MGB probe, non-primer limited) - FAQs (4333760T, 4352930E, 4333760F)

8 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.

Are there any TaqMan Pre-Developed Assay Reagents (PDARs) that have not been made obsolete?

The PDARs for several genes were simply renamed as the TaqMan Endogenous Controls and are available in the different tube sizes in FAM/MGB and VIC/MGB dye and quencher combinations. Those genes are: 18S rRNA; GAPDH; ACTB; TBP; PGK1; GUSB; PPIA; B2M; RPLP0; and TFRC.

Will TaqMan Gene Expression Assays work similarly to PDARs?

The TaqMan Gene Expression Assays that were created as replacements for the PDARs were designed with exactly the same sequence as the PDAR. Additionally, the assays are formulated with the same primer and probe concentration in a 20X solution and are available in 250 reaction size. There is virtually no difference between the PDAR and its replacement assay.

I am trying to recreate a gene expression experiment that used the discontinued PDAR (Pre-Developed Assay Reagents) products. Can I find a TaqMan Gene Expression Assay with the same sequence?

Yes, we have maintained a TaqMan Gene Expression Assay ID for each PDAR that was available in the past. This assay uses the exact same sequence as the PDAR, and is denoted by a series of five “9's” in the assay ID (example: Hs99999070_m1 is the old PDAR for the gene VEGF).

What can I use as an alternative to TaqMan Pre-Developed Assay Reagents (PDARs)?

The TaqMan Gene Expression Assays are the improved alternative for the PDARs. With over 400,000 pre-designed assays for human, mouse, and rat designed over most exon-exon junctions of transcripts in the public RefSeq database, chances are good that you will find the right assay for your experiment. Many assays are available for each gene because assays are designed for each transcript. Therefore, TaqMan Gene Expression Assays will enable you to detect different expression levels for splice variants of genes.

What are the key features of a TaqMan MGB probe?

TaqMan MGB probes have a nonfluorescent quencher at the 3´ end and a minor groove binder at the 3´ end that increases the melting temperature (Tm) of probe, allowing the use of shorter probes.  For more information on MGB probes, please consult the following manual: "Primer Express v1.5 and TaqMan MGB Probes for Allelic Discrimination: All PCR Instruments: User Bulletin." You can find a copy on our website by entering this title in the main search box.

When using the TaqMan Gene Signature Plates, should I mix the reactions after adding the master mix and template to the wells containing lyophilized primers and probe?

No, but it is recommended that the plate be centrifuged to draw down the liquid to the bottom of the wells.

What are your recommendations for the best way to dilute and store my TaqMan probe?

The probe should be diluted in TE buffer [10 mM Tris-HCl, pH 8.0 (at 25°C), 1 mM EDTA]. We recommend storing your probes, both stocks and working solutions, at -20°C in aliquots. This is to cut down on the number of times the probe is subject to freeze-thaws. For detailed information on diluting primers and probes, please refer to the tutorial entitled "Reconstituting and Diluting Primers and TaqMan Probes". You can find it on our website by entering this title in the main search field.

Find additional tips, troubleshooting help, and resources within ourTaqMan Primers and Probes Support Center.