Which of the following is/are true about PCR except:
Uses heat labile DNA polymerase
Uses heat stable DNA polymerase
Is technique for DNA amplification
Used to yield multiple copies of DNA
Ans: A (Uses....) "Reverse transcriptase- PCR is used for qua notification ofRNA Harper 30th/459, Lippincott 6th/ 483Polymerase Chain ReactionPCR provides a sensitive, selective & extremely rapid means of amplifying a desired sequence of DNA. Twenty cycles provide an amplification'* of lO^S 30 cycles of 109 -Harper 27th/410-llSpecificity* is based on the use of two oligonucleotide primers that hybridize to complementary sequence on opposite strands of DNA & flank the target sequenceDouble stranded DNA can be disrupted by beat or high pH, giving rise to single stranded DNA. The single stranded DNAserves as a template for synthesis of a complementary strand by replicating enzymes, DNA polymeraseEarly PCR reaction used an PS coli DNA polymerase that was destroyed by each heat denaturation cycle. Substitution of a heat-stable DNA polymerase (Taq polymerase) 5 from Thermus aquaticus, obviates this problem & has made possible automation of the reaction, since the polymerase reactions can be run at 70,]CPCR is a cyclic process & cycle contains three steps that involves {Chatterjea & Shinde)Denaturation of DNA duplex (94-98degC)Annealing of primers (37-60oC)Extension of the primers with a polymerase in the presence of dNTP (about 72,:C)Use of PCRIn detection of bacterial infections .retroviral infection & latent virusApplication in forensic medicine(r)in prenatal diagnosis - in diagnosis of inherited diseaseIn cancer detectionQIn transplantationTo study evolutionIn sex determination ofembry-osTo determine viral loadIn DNA sequencingFig,; Steps in one cycle of the polymerase chain reaction.
Immunology