#Question id: 31356
#Unit 14. Methods in Biology
#Question id: 40547
#Unit 14. Methods in Biology
In ‘TaqMan’ assay for detection of base substitutions (DNA variants), probes (oligonucleotides) with fluorescent dyes at the 5′-end and quencher at 3′-end are used. While the probe is intact, the proximity of the quencher reduces the fluorescence emitted by reporter dye. If the target sequences (wild type or variant) are present, the probe anneals to the target sequence, down stream to one of the primers used for amplifying DNA sequence flanking the position of variants. For an assay two flanking PCR primers, two probes corresponding to the wild type and variant allele and labeled with two different reporter dyes and quencher were used. During extension the probe may be cleaved by the Taq-polymerase separating the reporter dye and the quencher. Three individuals were genotyped using the assay. Sample for individual I shows maximum fluorescence for the dye attached to the wild type probe, sample for individual II shows maximum fluorescence for the dye attached to variant probe and sample for individual III exhibits equal fluorescence for both the dyes. Which of the following is correct?
#Question id: 40548
#Unit 14. Methods in Biology
Molecular beacons (MB) and Taqman (TQ) are used as probes in Real time PCR experiments. Both these probes are based on the principle of FRET and employ a fluorophor (F) and a quencher (Q). However the mechanisms by which they function are different as illustrated below
At what stage of the PCR we would be able to detect fluorescence?
#Question id: 12740
#Unit 14. Methods in Biology
#Question id: 12741
#Unit 14. Methods in Biology
#Question id: 12742
#Unit 14. Methods in Biology