What is primer extension reaction?
Primer extension is another technique used to analyze RNA structure and expression. In this method, an oligonucleotide primer is annealed to RNA and extended to a cDNA copy by reverse transcriptase in the presence of labeled dNTPs. Alternately, the primer is labeled and no label is included in the extension reaction.
What is a primer extension assay?
In the primer extension assay, the transcription start site for a gene is determined experimentally by identifying the 5′ end of the encoded messenger RNA (mRNA).
What are the reasons for using a fluorescently Labelled primer in TRLP?
By using fluorescently labeled primers, the use of hazardous radioactive isotope labeled reagents can be avoided and processing times are reduced as products can be detected during the electrophoresis procedure.
Is 6 FAM the same as FAM?
The single isomer, 6-FAM, contains a carboxylic acid that can be used to react with primary amines via carbodiimide activation of the carboxylic acid.
What is the difference between TM and annealing temperature?
The melting temperature (Tm) is the temperature at which 50% of the double-stranded DNA is changed to single-stranded DNA. The annealing temperature is the temperature used in the annealing step of a PCR reaction, which is highly dependent on the Tm of primers.
Why should unincorporated [γ-32P]ATP molecules be removed from the primer preparation?
Unincorporated [γ-32P]ATP molecules should be removed from the primer preparation to prevent them from interfering with the primer extension reactions and, in particular, with gel electrophoresis and autoradiography.
What should the final TM for both primers be?
The final Tmfor both primers should differ by no more than 5 °C. Di-nucleotide repeats (e.g., GCGCGCGCGC or ATATATATAT) or single base runs (e.g., AAAAA or CCCCC) should be avoided as they can cause slipping along the primed segment of DNA and or hairpin loop structures to form.
Why is primers design important in PCR experiments?
Designing appropriate primers is essential to the successful outcome of a PCR experiment.
What is the primer made of?
The primer is 5′-end-labeled using [γ-32P]ATP and T4 polynucleotide kinase and is annealed to the specific mRNA molecules within an RNA sample.