How would you use cDNA libraries to study the effect of a drug on gene expression in cancer cells?

• A. Use restriction enzymes to cut mRNA from cancer cells, insert into vectors, sequence to identify changes in gene expression.
• B. Treat cancer cells with the drug, isolate mRNA, create cDNA libraries, sequence to identify changes in gene expression.
• C. Isolate genomic DNA from cancer cells, create genomic libraries, sequence to identify changes in gene expression.
• D. Treat cancer cells with the drug, isolate proteins, create cDNA libraries, sequence to identify changes in gene expression.

Answer: (B)