Question

Describe the role of complementary base pairing during RT-PCR, DNA microarray analysis, RNA sequencing, and CRISPR-Cas9 editing.

Short answer

RT-PCR, DNA microarray analysis, and RNA sequencing uses complementary base-pairing to synthesize cDNA (complementary deoxyribonucleic acid) molecules.

The CRISPR-Cas9 complex's guide RNA, on the other hand, uses complementary base pairing to bind the genome for editing.

Step-by-step solution

Role of complementary base pairing in RT-PCR

In RT-PCR (Reverse transcriptase-Polymerase chain reaction), mRNA is used to synthesize complementary DNA (cDNA) molecules. Reverse transcriptase is the enzyme that uses mRNA as a template to synthesize the first strand of cDNA using complementary base pairing.

The first strand of DNA is then used by DNA polymerase to synthesize the second strand of DNA to form the cDNA molecule. Moreover, primers base pair with the target sequence through complementary base-pairing.

Role of complementary base pairing in DNA microarray analysis

DNA microarray assays are used to study genome expression. The mRNA from the cells is reverse-transcribed to synthesize cDNA, which is then labeled with fluorescent dyes.

These labeled cDNA molecules are then used as probes that bind to the target DNA sequence using complementary base pairing.

Role of complementary base pairing in RNA sequencing

In RNA sequencing, mRNA molecules are isolated and cut into smaller pieces. These mRNA pieces are used to synthesize cDNA through complementary base-pairing. The cDNAs are then sequenced and mapped by computer.

Role of complementary base pairing in CRISPR-Cas9

In the CRISPR-Cas9 system, Cas9 protein and guide RNA forms a complex to form Cas-9-guide RNA complex. The RNA guide is complementary to the target DNA. Thus, the RNA guide in the complex base pairs with the target gene through complementary base pairing and cuts the target DNA.