Quiz 10

PCR and DNA Sequencing

• The first step of PCR requires that the DNA to be amplified is prepared.
• The chain-termination method of sequencing relies on the formation of partial copies of the DNA fragment that terminate at each position in the sequence.
• The terminating nucleotide is identified by separating the fragments by size.

DNA Libraries

• A genomic library is a collection of plasmids, each containing different chromosomal fragments from the genome of an organism.
• A cDNA library contains only the expressed genes from the genome of an organism.

Gene Expression and Regulation

• Overexpression of genes in zebrafish can be achieved by microinjection of mRNA.
• If a protein with a specific function is isolated, the encoding gene can be identified by using the protein to screen a library.

Agarose Gel Electrophoresis

• DNA migrates through the pores of an agarose gel toward the positive electrode.
• Larger fragments travel more slowly.

Gene Expression Analysis

• Unlike RNA-seq, in situ hybridization can reveal the spatial distribution of gene expression.

Restriction Enzymes and DNA Fingerprinting

• Restriction enzymes cut DNA at specific recognition sites.
• DNA fingerprinting uses DNA sequences in the genomes of individuals that are hypervariable.
• The regions analyzed in DNA fingerprinting are called variable number tandem repeats (VNTRs).

Explore the basics of PCR, DNA sequencing, and DNA libraries. Learn about the preparation of DNA, chain-termination method, and genomic libraries.