Patent ID: 7846659

Claim:
An array of oligonucleotide probes immobilized on a solid support, the array comprising at least two sets of oligonucleotide probes, (1) a first probe set comprising a plurality of probes, each probe comprising a segment of at least three nucleotides exactly complementary to a subsequence of a reference sequence, the segment including at least one interrogation position complementary to a corresponding nucleotide in the reference sequence, (2) a second probe set comprising a corresponding probe for each probe in first probe set, the corresponding probe in the second probe set being identical to a sequence comprising the corresponding probe from the first probe set or a subsequence of at least three nucleotides thereof that includes the at least one interrogation position, except that the at least one interrogation position is occupied by a different nucleotide in each of the two corresponding probes from the first and second probe sets; wherein the probes in the first probe set have at least three interrogation positions respectively corresponding to each of three contiguous nucleotides in the reference sequence; provided that the array does not contain a complete set of probes of a given length, wherein a complete set is all permutations of nucleotides A,C, G and T/U: and wherein the reference sequence is from a biotransformation gene, wherein said biotransformation gene encodes an enzyme that is a reductase, an oxidase, a hydrolase or a transferase.