Objective:To design hair clamp probe and the probes with single extending arm detecting embB306codon of Ethambutol resis-tant Mycobacterium tuberculosis bacterium(MTB)

meanwhile

to design fair clamp probe chip and detecting fluorescence signal from hy-bridization between the amplified product and probe by fluorescence microscope.Methods:The software

Beacon designer

was used to de-sign fair clamp probe and the probes with single extending arm detecting embB303codon and detecting fluorescence signal from hybridiza-tion between the amplified product and probe

and confer to the sequencing results.Results:The difference between PCR products from standard strain and ethambutol resistant one was obvious in detecting the fluorescent light with fluorescence microscope.We detected fluo-rescent light signal between the 33 ethambutol resistant strains and 10 H37RV standard strains.The rate of resistant ethambutol detected with hair clamp probe was about 66%

and the rate of sequencing was about 69%.Conclusions:The mutation site of embB306codon of MTB is the main reason of ethambutol resistant MTB.The technology of fair clamp DNA probe chip can effectively detect mutation of single base site.Fluorescence microscope can sensitivily detect the site of hybridization on fluorescence chip.