On bleach
Moss and Fiona,
I was the first person on the board to cite the Kemp/Smith paper, in comments #1018 and 1286, which deals with the decontamination of bone. It is you who are ignoring the more relevant Prince/Andrus citation, which I first made in #1289. This paper shows that a 10% dilution of commercial bleach is more effective than an approximately 16% dilution of concentrated hydrochloric acid.
BobTheDonkey,
I noted that commercial bleach is about 5% sodium hypochorite in water in a previous comment. A 10% solution means to take 1 part full strength (5%) bleach and mix with 9 parts water. A 2% solution means to take 1 part bleach and 49 parts water. Note that the Promega technical bulletin I cited says that one must thoroughly rinse away the 2% bleach solution, or the remainder will harm the DNA of interest. In other words even a dilution of dilute bleach residue can destroy DNA.
Alt+F4,
Dr, Johnson’s argument, which I have referenced in a previous comment, is that cleaning would remove DNA before blood, period. The notion that cleaning with bleach will remove all traces of blood without removing all DNA strikes me as particularly strange, given the mechanisms by which bleach can act. Sollecito’s words, or Mignini’s for that matter, cannot conjure up DNA that cannot be on the blade.
Chris