This is a repeat of yesterday’s PCR with a fresh working stock in hopes of eliminating the source of contamination seen in the negative control yesterday.

Lane 1 – 100bp ladder

Lane 2 – 5/13 DNA

Lane 3 – 5/26 DNA

Lane 4 – Empty

Lane 5 – H2O

Results: Same problem as yesterday. Water sample is contaminated. This suggests that the primer stocks are contaminated. Likely due to the use of non-sterile, “old” TE for reconstitution of the primer stocks. Will re-order them and reconstitute them sterily.