Question

Which one of the following techniques can be used to compare the expression of a large number of genes in two biological samples in a single experiment?

• A. Polymerase chain reaction
• B. DNA microarray
• C. Northern hybridization
• D. Southern hybridization

Hint:

DNA microarrays allow researchers to simultaneously measure the expression levels of thousands of genes, making them an invaluable tool for studying gene expression patterns.

Answer 1

The Correct Option is B

DNA microarray technology is used to measure the expression levels of thousands of genes simultaneously in a single experiment. It involves hybridizing cDNA or RNA samples from two biological samples onto a slide with complementary DNA probes, allowing the comparison of gene expression profiles.

(1) DNA Microarray:
- DNA microarrays can detect the expression of a large number of genes in parallel, making it a powerful tool for high-throughput gene expression studies.
- This technique can be used to compare gene expression levels between different biological samples, such as healthy vs. diseased tissue.

(2) Why Other Options Are Incorrect:
- Polymerase chain reaction (PCR) (Option 1) is a technique used to amplify specific DNA sequences. It is not suitable for comparing the expression of a large number of genes simultaneously.
- Northern hybridization (Option 3) is a technique used to detect specific RNA sequences, but it is less efficient and typically involves detecting the expression of fewer genes compared to DNA microarrays.
- Southern hybridization (Option 4) is used to detect specific DNA sequences, not gene expression. It is not suitable for comparing large numbers of genes in two samples.

Conclusion: The most appropriate technique for comparing the expression of a large number of genes in two biological samples in a single experiment is the DNA microarray.