Also published as: Aaron P Johnson, Adam Johnson, Alexandra M Johnson, Amelie Johnson, Andrew D Johnson, Andrew Johnson, Bailee Johnson, Benjamin B Johnson, Benjamin Johnson, Benjamin T Johnson, Brandon M Johnson, Brendan J Johnson, Brent A Johnson, Bruce E Johnson, Caitlin V Johnson, Catherine Johnson, Catherine O Johnson, Chelsea N Johnson, Chris Johnson, Christopher M Johnson, Christopher N Johnson, Colin A Johnson, Corbin S C Johnson, Derek R Johnson, Douglas B Johnson, Douglas S Johnson, Dymonn Johnson, E W Johnson, Elaine Johnson, Elizabeth J Johnson, Emma F Johnson, Eric C Johnson, Eric Johnson, Eric O Johnson, Erik C B Johnson, G L Johnson, G S Johnson, Gary L Johnson, Gary S Johnson, Ian T Johnson, Ivy Johnson, J Patrick Johnson, Jane E Johnson, Jared L Johnson, Jeremy Johnson, Jodie Johnson, John P Johnson, Josephine P Johnson, Joshua W Johnson, Judith Johnson, Julie A Johnson, K R Johnson, Kamin J Johnson, Karen C Johnson, Katherine J Johnson, Keith A Johnson, Keith Johnson, Kelsey E Johnson, Kenneth W Johnson, Kevin A Johnson, Kevin Johnson, Kipp W Johnson, Kirby D Johnson, Kory R Johnson, Lacey Johnson, Lance A Johnson, Lance Johnson, Lauren J Johnson, Linda S B Johnson, Linda S Johnson, LuAnn K Johnson, Mark Johnson, Mary M Johnson, Maryann Johnson, Matthew E Johnson, Matthew P Johnson, Maya R Johnson, Melvin G Johnson, Michael Johnson, Morgan Johnson, Myriam Johnson, N L Johnson, Nancy L Johnson, Nicholas A Johnson, Nicholas J Johnson, Nicholas Johnson, Nicholas L Johnson, Nicole Johnson, Patrick W Johnson, Paul Johnson, Paul R V Johnson, Philip E Johnson, R C Johnson, Rachel M Johnson, Randi K Johnson, Randy L Johnson, Rebecca H Johnson, Renee Johnson, Richard J Johnson, Robert Johnson, Rodney W Johnson, Scott M Johnson, Simon C Johnson, Stephanie Johnson, Sterling C Johnson, Sterling Johnson, Theron Johnson, Tierra A Johnson, Timothy S Johnson, Toby Johnson, Tory P Johnson, Tracy L Johnson, Tyler B Johnson, W Evan Johnson, W G Johnson, Warren Johnson, Zoë Johnson
The effect of caffeine on postreplication repair, as seen in alkaline sucrose gradients, conjugation, and ultraviolet light (UV) survival, was studied in excision deficient strains of Escherichia coli Show more
The effect of caffeine on postreplication repair, as seen in alkaline sucrose gradients, conjugation, and ultraviolet light (UV) survival, was studied in excision deficient strains of Escherichia coli K12 and B. A caffeine concentration of 2 mg/ml was chosen for the study which did not inhibit colony formation. Both E. coli K12 AB2500 and E. coli B WWP2 were more sensitive to UV when plated on caffeine plates. Conjugation was not inhibited in the E. coli K12 strain; however, the same procedure confirmed caffeine inhibition in the E. coli B strain [17]. Caffeine did not inhibit postreplication repair in either strain, as determined by sedimentation profile studies of DNA on alkaline sucrose gradients. No strand breakage or degradation was observed in parental or post-UV replicated DNA for as long as 50 min incubation in caffeine. Thus caffeine concentrations that inhibited two recA gene product related phenomena did not cause immediate changes in size of DNA or inhibit the rate of a DNA gap generating postreplication type of DNA repair. Show less