Teaching and traveling are over for a while, so I'm back at the bench, ready to grapple once more with the miasma of irreproducibility hanging over my GFAJ-1 growth experiments.
I'm going to repeat an experiment I did in September, testing growth with different levels of arsenate and phosphate in plastic and glass screw-cap tubes. That time I only followed growth by changes in turbidity of the cultures, but this time I'll also follow the changes in the numbers of viable cells by plating samples on agar medium. I'll start the cultures tomorrow morning, plating the cells at t=0, so I know how many viable cells I started with, and again at t=1 hr, to see if cells are immediately dying in the arsenate. Then I'll plate at about 8 hr (after a family dinner, it being Sunday), and again the next morning.
The first step is to clean up all the old cultures on my bench this evening, so I'm ready to go in the morning...
11 hours ago in Variety of Life