Brown: Team Resistance/9 July 2008

9 July 2008

• OPTICAL DENSITY TEST:
• We made multiple solutions of pVJ4 and added varying amounts of Arabinose to determine how long complete lysis takes. We also added Chloramphenicol (1:1 ratio) in addition to Arabinose to see whether it would speed up lysis.

• Initial OD 50mL culture: .038

  .2%(1)   .2%(2)   .4%(1)  .4%(2)  .2% + Chloramphenicol(1)  .2% + Chloramphenicol(2)  Control
 1 .084     .085      .079   .079       .062                        .053                  .073
 2 .065     .069      .040   .048       .044                        .047                  .076
 3 .018     .018      .023   .021       .034                        .050                  .075
 4 .014     .015      .013   .013       .050                        .044                  .071

• The first few readings indicated an increase in the optical density. This is to be expected because the bacteria are in the mid-log phase and still growing. Growth must occur in order for the S, R, and Rz genes to be expressed and translated. Cell lysis is complete in four hours.
• The addition of Chloramphenicol did not alter the rate of lysis.