Question

Researchers are looking for better treatments for breast cancer. For a particular DNA microarray assay (DNA chip), cDNA has been made from the mRNAs of a dozen patients' breast tumor biopsies. The researchers will be looking for a?

1) particular gene that is amplified in all or most of the patient samples.
2) pattern of fluorescence that indicates which cells are overproliferating.
3) pattern shared among some or all of the samples that indicates gene expression differing from control samples.
4) group of cDNAs that act differently from those on the rest of the grid.
5) group of cDNAs that match those in non-breast-cancer control samples from the same population.

Answer 1

Researchers using DNA microarray analysis in breast cancer studies aim to identify gene expression patterns in tumor biopsies that differ from those in control samples. This can reveal specific genes involved in cancer, potentially leading to better treatments. so, option 3 is the correct answer.

Step-by-step explanation:

Researchers utilizing DNA microarray technology are primarily looking for patterns of gene expression that differ between the breast tumor biopsies of patients and control samples of non-cancerous cells. DNA microarrays, or 'DNA chips', allow for the comparative analysis of hundreds to thousands of genes simultaneously by measuring the brightness of fluorescent signals emitted by hybridized cDNA, providing insights into which genes are active or inactive within cancerous cells compared to healthy ones.

In the context of breast cancer research, the focus would be on option 3) identifying a pattern shared among some or all of the samples that indicates gene expression differing from control samples. This may include detecting specific genes that are upregulated or downregulated in tumor cells. It's a powerful technique that can help pinpoint potentially faulty genes or pathways involved in cancer development, aiding in the discovery of new therapeutic targets.