Mezclas maestras de PCR TaqMan™ Universal

We recommend using either the TaqPath ProAmp Master Mix or the TaqMan Genotyping Master Mix. The TaqMan Genotyping Master Mix has the advantage of proven performance with up to 3 days of pre- and post-PCR stability, allowing you to set up plates ahead of time or read the plates later (see the data here, https://tools.thermofisher.com/content/sfs/brochures/cms_039236.pdf) while the TaqPath ProAmp Master Mix can handle samples that may have inhibitors present.

miRBase continues to re-annotate the miRNA sequences as more information becomes available. A sequence that once mapped to a given species (e.g.: human) may no longer exist, so it is removed from miRBase. Accordingly, the original assay for that sequence no longer maps to an annotated miRNA, and as a result the annotation fields on the search results page on the Thermo Fisher Scientific portal are empty. An example of this is Assay “hsa-miR-505” (Assay ID 001049). miRBase continues to re-annotate the miRNA sequences as more information becomes available. A sequence that once mapped to a given species (e.g.: human) may no longer exist, so it is removed from miRBase. Accordingly, the original assay for that sequence no longer maps to an annotated miRNA, and as a result the annotation fields on the search results page on the Thermo Fisher Scientific portal are empty. An example of this is Assay “hsa-miR-505” (Assay ID 001049).

A TaqMan MicroRNA Assay has two components: an RT reaction containing a miRNA specific stem-loop reverse-transcription primer and a separate specific TaqMan miRNA Assay. The RT stem-loop primer provides the specificity for the mature miRNA target; it does not detect its precursor. The formation of a RT primer/mature miRNA-chimera extends the length of the 5’ end of the miRNA. The longer RT product provides a miRNA specific cDNA template amenable to the TaqMan assay design.

There are 2 steps involved in using the TaqMan MicroRNA Assays:

1. RT step: total RNA to cDNA using miRNA-specific RT primers from the TaqMan MicroRNA Assays and the TaqMan MicroRNA Reverse Transcription Kit (P/N 4366596, 200 reactions or 4366597, 1000 reactions)

2. PCR step: cDNA to PCR products using primers and probe from the TaqMan MicroRNA Assays together with TaqMan Universal PCR Master Mix No AmpErase UNG (P/N 4324018).

MicroRNAs are believed to play an important role in post transcriptional gene regulation. A total of ~850 unique miRNAs have been discovered so far, including ~333 human miRNAs. They are relatively abundant, ranging from a few to as many as 50,000 molecules per cell. They account for approximately 1% of the predicted genes in animals and plants. The level of individual miRNAs varies dramatically across cell type and developmental stages. These differences in miRNA level are believed to be a key indicator of miRNA activity.

Recent research has implicated miRNAs in the following: cell development, differentiation, communication and cell death; DNA methylation and chromatin modification; metabolism; human cancer development; haematopoiesis; nervous system patterning; insulin secretion.