The addition of low numbers of 3' thymine bases can be used to improve the hybridization signal of oligonucleotides for use within arrays on nylon supports.

Oligonucleotide arrays can be used for the analysis of microbial nucleic acid. The addition of high numbers of dTTP to the 3' ends of oligonucleotides using terminal transferase has been shown to facilitate membrane binding. This paper demonstrates low numbers of thymine bases added to the 3' end of oligonucleotides during synthesis can improve hybridisation signal intensity where the signal seen with the unmodified oligonucleotides is poor. Thus, the addition of variable numbers of thymine bases to different oligonucleotides allows the production of oligonucleotide arrays producing strong interpretable hybridisation signals.