Abstract: Novel pro-drugs and methods for their use to alter the growth and biological characteristics of living cells, tissues, or whole organisms are described. The methods allow for selective activation of the pro-drugs at or near transformant host cells expressing a gene for an enzyme that activates the pro-drugs. Pro-drugs according to a preferred embodiment of the invention are conjugates of a bioactive compound and a chemical group that is capable of being cleaved from the bioactive compound by action of an enzyme. Methods according to this invention include, (a) introducing into targeted cells a gene encoding an enzyme and (b) administering a pro-drug, wherein the enzyme releases the pro-drug from conjugation. In a preferred embodiment of the invention, the gene encoding the enzyme is a marker gene.

Abstract: A characteristic intensity of a feature in image data generated by scanning a microarray probe is determined. A set of pixels of the image data that nominally represent the feature is identified. The pixels each have an value (such as an intensity value) associated therewith. For each of a plurality of subsets of the set of pixels, a variation statistic value is determined that corresponds to a variation in the values associated with the pixels of that subset. One of the subsets of pixels is chosen based on the determined variation statistic values. A method is also described to relate a first expression array of probes to a second expression array of probes. A subset of the probe for the arrays is determined based on a comparison of the ordering of the subset of the probes of the second array, according to a particular characteristic of the probes, to the ordering of corresponding probes in the first array according to the particular characteristic of the probes.