Assessment of Low Level Laser (808 nm) Effects on E.coli -DH5α Viability and Growth

NIR Laser application in bacteria is often focused on mortality and antibiotic efficacy. The literature records on this point are absolutely diverse from mortality in different degrees to immortality and even viability enhancement. The aim of this study is to investigate 808 nm laser effects on E.coli-DH5α viability and Growth with CFU, MTT and FCM assays. To obtain the purpose, bacteria in LB media put on with 808nm laser on 100 and 200 J/cm2 dosages and were investigated and compared by CFU, MTT and FCM assay. CFU assay results after 24 hours incubation were not significantly different between laser treatments and control. (P=0.06). In contrast, MTT assay results after 1 hours from laser treatment indicated significant deleterious effects in 200 J/cm2 laser treatment compared with control(P=0.006). On the other hand, FCM assay results of laser treatments with using of PI and Triton X100 not only approved MTT assay results but also revealed some dose dependent changes on bacteria ranging from increase membrane permeability to lethal damages. As a conclusion of the results in these method assays, we can state that these different laser doses produce diverse effects on viability and growth in E.coli-DH5α. Consequently the laser treatments could be planned for antibiotic purposes or enhancing gene transformation process.