PCR and RTPCR can be used to quantify DNA and RNA levels Ass

PCR and RT-PCR can be used to quantify DNA and RNA levels. Assuming that each step of the PCR process is 100% efficient, how many copies of a template would be amplified after 30 cycles of a PCR reaction if the number of starting template molecules were:

a. 10

b. 1,000

c. 10,000

Solution

There is exponential increase in number of DNA molecules produced with each cycle of PCR. So, if there is one double stranded DNA molecule i.e. two template strands, the number of DNA molecules produced after n cycles of PCR would be= 2ⁿ.
Also, after two rounds of PCR, 4 template strands would be amplified (2 dsDNA molecules= 4 template strands).
So, after 30 cycles, the number of DNA molecules produced from one double stranded DNA= 2²⁸= 2.68x10⁸
a.) If the number of template strands are 10, the copies of templates amplified after 30 cycles = 10 X 2²⁸= 2.68x10⁹ molecules
b.) If the number of template strands are 1000, the copies of templates amplified after 30 cycles= 1,000 X 2²⁸= 2.68x10¹¹ molecues
c.) If the number of template strands are 10,000, the copies of templates amplified after 30 cycles= 10,000 X 2²⁸= 2.68x10¹² molecues