The Checklist for Plating Competitions

• Before plating, it is important to transfer and mix correctly from the competition plates. The following are guidelines that should be followed EXACTLY:

1. Fill plates with 900 µl saline.
2. For initial or long-term plating, only one saline plate per competition plate is necessary. However, for final plating, two 900 µl saline plates are needed for each competition plate since there will be no transfer to fresh media.
3. Clean the pin tool by dipping it five times into 10% bleach, then onto lint-free paper. Next, dip the pin tool five times into ddH₂O, then onto lint-free paper. Again, dip the pin tool five times into ddH₂O, then onto lint-free paper. Next, with caution, dip the pin tool five times into isopropanol, then pass through Bunsen burner flame.
4. Transfer 3.5 µl: using the pin tool, pass through the meniscus and move to the bottom of the plate five times and transfer to the next competition plate. This step is the first 257.1x dilution.
5. Mix this plate thoroughly by moving the pin tool in a circular motion and up and down simultaneously. Be sure to pass through the meniscus each time. The motion is similar to that of churning butter.
6. Clean the pin tool as described above.
7. Transfer 3.5 µl: using the pin tool, pass through the meniscus and move to the bottom of the plate five times and transfer to the next competition plate. This step is the second 257.1x dilution.
8. Mix this saline plate thoroughly by moving the pin tool in a circular motion and up and down simultaneously. Be sure to pass through the meniscus each time. The motion is similar to that of churning butter.
9. The cells are present in the plate in a checkerboard pattern, with odd-numbered rows starting on the first well and even-numbered rows starting on the second well. As a result, there are six populations per row. Plate 5 µl of diluted cells and 50 µl of saline on TA (tetrazolium arabinose) plates.

-- Main.MarkKauth - 22 May 2008