What is the sensitivity of the microarrays?
Sensitivity is dependent on the labeling and detection methods used. Obviously, those who use amplification techniques to label the samples will achieve much better sensitivity over the standard labeling methods. Conversely, the amount of RNA you can isolate dictates the type of labeling method or amplification method you will be able to use. In general, the amount of effort and experimental risk increases as the amount of RNA starting material decreases. There are published reports describing the use of extremely limited RNA for doing microarray analyses, but these methods may require some dedicated development time within your lab to get them working properly. See types of labeling methods for more information. Another point to remember is that sensitivity can vary with every labeling reaction and hybridization, so performing replicates is important.
