The invention provides methods for preparing reagent sets based on small subsets of highly informative genes capable of carrying out a broad range of chemogenomic classification tasks. The invention also provides high-throughput diagnostic assays and devices based on these reduced subsets of information rich genes. In addition, the invention provides a general method for selecting a reduced subset of highly responsive variables from a much larger multivariate dataset, and thus, use of these variables to prepare diagnostic measurement devices, or other analytic tools, with little or no loss of performance relative to devices or tools incorporating the full set of variables.