- Get the GFAJ-1 cells growing in liquid ML60 medium (with vitamins and trace elements) at least as well as they grew for Wolfe-Simon et al. That means at least two doublings a day.
- Do preliminary growth curves to find out what phosphate concentrations limit growth.
- Grow a big batch of cells under phosphate-limiting conditions. Collect them and freeze them when they are still growing exponentially (so no complications due to accumulation of poly-hydroxybutyrate granules).
- Do meticulous growth curves with different concentrations of added phosphate with and without 40 mM arsenate. Also try media with no added phosphate, in case my phosphate-contamination levels are like those in the paper.
- Grow enough cells at the lowest phosphate level, with and without arsenate, that I can purify enough DNA for analysis.
- Send the DNA and samples of the various media to Leonid Krugliak and Josh Rabinowitz, who will use mass spectrometry to measure phosphorus and arsenic levels. I'm waiting for them to tell me the sample sizes they'll need.
I'll also ask the RA to order the universal 16S rDNA primers so we can use PCR and DNA sequencing to confirm that the cells I'm growing are indeed GFAJ-1.