Abstract: Objective To establish a method based on visible microplate chip for the detection of rifampicin and isoniazid resistance to Mycobacterium tuberculosis. Methods Gene chip was constructed by immobilizing default mode probes against genes associated with rifampicin and isoniazid resistance to Mycobacterium tuberculosis on the surface of gene chip. Drug resistance was identified by the prepared gene chip to detect the relative gene mutation, and the positive results,a color dot on the surface of gene chip,can be observed by naked eye. Results The prepared visible microplate chip showed stable detection results. The 40 of 50 (80%) strains were resistant to isoniazid with a high mutation site of 315 codon within katG gene, and 15 of 20 (75%) strains were resistant to rifampicin with a high mutation site of 531 and 526 codons within rpoB gene. The results from the gene chip detection were consistent with the polymerase chain reaction(PCR)sequencing analysis. Conclusions The prepared visible microplate chip with good specificity and sensitivity is a fast, accurate and convenient mothod, and is promising for the detection of rifampicin and isoniazid resistance to Mycobacterium tuberculosis.

Key words: Microplate chip, Mycobacterium tuberculosis, Drug resistance, Rifampicin, Isoniazid