The BIOARRAY™ 3’-OH Terminal Labeling System is the gold standard end-labeling system for use with Affymetrix DNA SNP, Resequencing and Prokaryotic microarrays. The BIOARRAY™ Terminal Labeling Kit with Biotin-ddUTP has been developed for DNA probe array assays. This method uses Bio-ddUTP and terminal deoxynucleotide transferase to catalyze the addition of a single biotin-ddUMP to the 3’-OH terminus of an amplified and fragmented target DNA molecule. A standard reaction will label up to 100 picomoles (equivalent to 1µg of a 30-nucleotide sequence). When DNA fragments are labeled at the 3’-OH terminus, the sequence bias that occurs with either nick translation or random priming is eliminated.