Question

Northern blotting, RT-PCR, and microarrays can be used to analyze gene expression. A lab studies yeast cells, comparing their growth in two different sugars, glucose and galactose. One student is comparing expression of the gene HMG2 under these two conditions. Which technique(s) could he use and why? Another student wants to compare expression of all the genes on chromosome 4, of which there are approximately 800. What technique(s) could she use and why?

Answer 1

Which technique should be used to compare expression of the gene HMG2 under two different conditions?

RT-PCR is very much suitable for this. Since the student wants compare the expression of a gene in two different samples (conditions), RT-PCR is the best for this, as RT-PCR amplifies the gene of interest into multiple copies. If our gene of interest (HMG2) is expressed under the test conditions (glucose or galactose), we will see the amplified products. The number of copies of the gene product is directly proportional to the gene expression (comparative manner).

Microarrays are best to compare expression of all the genes on chromosome 4, of which there are approximately 800. This is because among northern blotting, RT-PCR, and microarrays, microarray is only used for studying multiple genes at a time.