No effect of femtosecond laser pulses on M13, E. coli, DNA, or protein.
Data showing what appears to be nonthermal inactivation of M13 bacteriophage (M13), Tobacco mosaic virus, Escherichia coli (E. coli), and Jurkatt T-cells following exposure to 80-fs pulses of laser radiation have been published. Interest in the mechanism led to attempts to reproduce the results for M13 and E. coli. Bacteriophage plaque-forming and bacteria colony-forming assays showed no inactivation of the microorganisms; therefore, model systems were used to see what, if any, damage might be occurring to biologically important molecules. Purified plasmid DNA (pUC19) and bovine serum albumin were exposed to and analyzed by agarose gel electrophoresis (AGE) and polyacrylamide gel electrophoresis (PAGE), respectively, and no effect was found. DNA and coat proteins extracted from laser-exposed M13 and analyzed by AGE or PAGE found no effect. Raman scattering by M13 in phosphate buffered saline was measured to determine if there was any physical interaction between M13 and femtosecond laser pulses, and none was found. Positive controls for the endpoints measured produced the expected results with the relevant assays. Using the published methods, we were unable to reproduce the inactivation results or to show any interaction between ultrashort laser pulses and buffer/water, DNA, protein, M13 bacteriophage, or E. coli.
Human Effectiveness Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, 711th Human Performance Wing, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234-2644.
Jeffrey C
JC
Wigle
Human Effectiveness Directorate, Bioeffects Division, Molecular Bioeffects Branch, 711th Human Performance Wing, Wright-Patterson AFB, Ohio 45433-5707 and Department of Chemistry, United States Air Force Academy, Colorado Springs, Colorado 80840-6230.
Eric A
EA
Holwitt
Conceptual MindWorks Inc., 9830 Colonnade Boulevard, San Antonio, Texas 78230.
Larry E
LE
Estlack
TASC Inc., 4241 Woodcock Drive, Suite B100, San Antonio, Texas 78228.
Gary D
GD
Noojin
Human Effectiveness Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, 711th Human Performance Wing, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234-2644.
Katharine E
KE
Saunders
University of Wisconsin-Milwaukee, Department of Physics, P. O. Box 413, Milwaukee, Wisconsin 53201.
Valdislav V
VV
Yakovlev
Human Effectiveness Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, 711th Human Performance Wing, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234-2644.
Benjamin A
BA
Rockwell
D000818:Animals; D017104:Bacteriophage M13 / Q000528:radiation effects*; D002021:Buffers; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000737:chemistry; D004279:DNA, Viral / Q000528:radiation effects*; D004586:Electrophoresis; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000528:radiation effects* / Q000821:virology; D006147:Guanine / Q000031:analogs & derivatives / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007834:Lasers; D046911:Macromolecular Substances; D010455:Peptides / Q000737:chemistry; D030421:Peroxynitrous Acid / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry; D048328:Potoroidae; D011506:Proteins / Q000737:chemistry*; D017382:Reactive Oxygen Species; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013601:T-Lymphocytes / Q000166:cytology; D013997:Time Factors; D014867:Water / Q000737:chemistry
C095838:8-nitroguanine; D002021:Buffers; D004279:DNA, Viral; C045076:Fenton's reagent; D046911:Macromolecular Substances; D010455:Peptides; D011506:Proteins; D017382:Reactive Oxygen Species; D014867:Water; D030421:Peroxynitrous Acid; D012710:Serum Albumin, Bovine; D006147:Guanine; D004247:DNA; D006861:Hydrogen Peroxide; D007501:Iron