Abstract:

Three fluorescent dyestufs，namely FDA,Rh1 23 and DCFH-DA,were used to stain Escherichia coli (E.coli),and the fluorescence spectrophotometer,the fluorescence microscopy and the TEM were adopted to observe‘ the membrane alteration of E.col radiated by ultrasonic.Th e results indicate that fluorescent probe is feasi-ble in the determ ination of the alteration of E.col membrane,and that,after be ing radiated by ultrasonic at 300 W and 25 kHz f0r 90 s,the cell maintains an integrated structure,but the double molecule layer of the membrane be -comes blurry,with apertures on the surface and with the content material penetrating to the oumide.Moreover,the membrane potential decreases by 26.7% while,in contrast,the memb rane perm eability increases by 12.7% ,with the ROS level significan tly improved.

Key words: cell membrane, ultrasonic, Escherichia coli