Q.87 A zoologist recovered some tissue from preserved skin of a woolly mammoth. Further
genetic analysis requires DNA isolation and increasing its amount. Which ONE of the
following techniques would be most useful for increasing the amount of DNA?
(A) RFLP analysis (B) Polymerase chain reaction (PCR)
(C) Electroporation (D) Chromatography

Polymerase Chain Reaction (PCR) is the most useful technique for increasing the amount of DNA from preserved woolly mammoth skin tissue, as it specifically amplifies targeted DNA segments exponentially.

Option Analysis

RFLP Analysis detects genetic variations by digesting DNA with restriction enzymes and comparing fragment lengths via gel electrophoresis, but it does not amplify DNA. This technique analyzes existing DNA amounts for polymorphism detection, making it unsuitable for boosting low-quantity ancient DNA.

Polymerase Chain Reaction (PCR) employs thermal cycling with primers, DNA polymerase, and nucleotides to replicate specific DNA regions millions of times, ideal for scarce samples like mammoth tissue. Studies confirm PCR’s routine use in amplifying woolly mammoth DNA from preserved specimens.

Electroporation applies electric pulses to create temporary cell membrane pores for introducing foreign DNA into living cells, not for amplifying extracted DNA. It serves transformation purposes, irrelevant here post-DNA isolation.

Chromatography separates DNA molecules by size, charge, or affinity in purification processes, yielding cleaner samples without increasing DNA quantity. It aids isolation but fails to multiply DNA copies.

Introduction: Woolly Mammoth DNA Amplification Using PCR
In genetic analysis of ancient specimens like woolly mammoth preserved skin, amplifying scarce DNA is crucial for further study. Polymerase Chain Reaction (PCR) stands out as the most effective technique to exponentially increase DNA amounts after isolation, enabling detailed sequencing and research. This approach is vital for CSIR NET aspirants studying molecular biology tools in paleogenetics.

Why PCR Excels in Ancient DNA Amplification
PCR mimics DNA replication through denaturation, annealing, and extension cycles, producing billions of copies from minimal templates. For woolly mammoths, researchers have successfully used PCR on bone and tissue extracts, overcoming degradation challenges. Unlike other methods, PCR targets specific regions, ensuring high yield for downstream applications like genome sequencing.

Evaluating Other Techniques for DNA Increase

• RFLP Analysis: Cuts DNA with enzymes to reveal polymorphisms but requires ample starting material and offers no amplification.

• Electroporation: Facilitates DNA uptake into cells via electric shocks, not relevant for cell-free DNA multiplication.

• Chromatography: Purifies DNA mixtures by separation but does not replicate molecules.

Applications in Woolly Mammoth Genetic Research
PCR has enabled full mitochondrial DNA sequencing from mammoth remains and even nuclear genome insights, revolutionizing de-extinction studies. For students, mastering PCR’s role in biotech exams like CSIR NET highlights its precision over analytical or delivery methods.