Last year NASA made a sensational claim about discovery
of DNA in which the phosphorous is
replaced by arsenic. The bacterial
strain GFAJ-1 was isolated from the arsenic-rich sediments of
California’s Mono Lake by its ability to grow in the artificial Mono Lake
medium without phosphate but with high concentrations of arsenate. It was
claimed that GFAJ-1 grew in -P medium only when arsenate was provided, and significant amounts of arsenate were detected
in subcellular fractions. This was
interpreted as “ growth due to use of
arsenate in place of phosphate”. Wolfe-Simon et
al. further reported that arsenic was incorporated into the
DNA backbone of GFAJ-1 in place of phosphorus, with an estimated 4% replacement of P by As based on
the As:P ratio measured in DNA samples embedded in agarose gel slices.
This
discovery claim by NASA Scientists was
sensational as
