This part provides background information on genomics and microarray, protocols, FAQs, and other related technical information. We strive to deliver useful information for both beginners and experienced investigators.
The complete GeneChip Expression Analysis Technical Manual, which inlcudes all GeneChip-related protocols, is available for downloading from Affymetrix. (needs a simple registration)
Is it possible to perform microarray analysis with ultra-small amount of RNA (say, 10ng)?
For GeneChip analyses, generally 5-20 µg of total RNA is needed. However, this is not to say that you cannot conduct microarray analyses with smaller amounts of RNA. Under certain circumtances, target tissues or cells are limited and as a result cannot provide the above specified amount of RNA sample. This is especially true if you use laser capture microdissection (LCM) to collect your target cells. Under these circumstances, total RNA as low as 10 ng, can still be used for GeneChip analysis. To produce enough targets for array hybridization, the original RNA sample is subjected to a signal amplification process with two-cycle target labeling. Single-cell microarray analyses have also been reported.