how are microarrays used?
The basic protocol is as follows: • Isolate the RNA you are interested in and the RNA from your control. The RNA can come from any cells. It is important to realize though that the RNA from tissues or any heterogenous cells may lead to results that reflect changes in the composition of the sample rather than in changes due to the experimental hypothesis. • Label the RNA. Usually this means preforming a reverse transcriptase reaction and incorporating dye that has been linked to a DNA nucleotide. however some protocols, i.e. Affymetrix’s, call for an amplification of the RNA and labelling of the RNA itself. For microarrays on nylon membranes usually the label is radioactive. • hybridize the labeled target to the microarray. This consists of placing a solution containing the labeled target on the microarry and letting it sit for a period of hours. This allows a given target to find it’s probe on the microarray and bind to it. Usually this is carried out a specific temperature to minimize
