Low-cost microarray platform to detect antibiotic resistance genes

Versatile DNA-based approaches for the detection of pathogens and antibiotic resistance genes have been introduced to facilitate faster diagnostic test. This requires a notable amount of cost-intensive commercially labelled DNA oligonucleotides in high-throughput assays. Here, we introduce an alternative method that utilizes a terminal deoxynucleotidyl transferase reaction to significantly reduce expenses of oligonucleotides. Antibiotic resistance genes that are of high clinical relevance were used as relevant application. The alternative labelling was based on an elongation step in the presence of biotin-conjugated nucleotides. Fluorescence-labelled streptavidin was bound to biotin-conjugated nucleotides and detected via a standard high-throughput microarray scanner. The self-labelled detection oligonucleotides performed equally well regarding sensitivity and specificity compared to commercially labelled ones, but at only 10% of their cost.