Previous PCRs from 20090601 & 20090602 both showed contamination in the negative control. Suspect that the primer stocks were contaminated due to the usage of older, non-sterile TE for reconstitution. New stocks were received and reconstituted with filter-sterilized TE. Working stocks were made with filter-sterilized Nanopure H2O. All pipettes, tips, tubes, racks were UV-sterilized in the biological hood. The PCR reaction was set up in the biological hood. PCR set up is here. Used universal 16s bacteria primers (27F, 1492R). Sequences from Sara Kelly. Anneal 60C.

Lane 1 – 100bp ladder

Lane 2 – gDNA (5/13/2009)

Lane 3 – gDNA (5/26/2009)

Lane 4 – H2O

Lane 5 – H2O

Lane 6 – H2O

Lane 7 – H2O

Results: Still contamination in the water-only samples!!!