Method: Long Term Lambda Phage Storage

June 7 1990

Srini Ramachandra

Purpose:

No special treatment is required to prepare a lysate for the active collection. The following procedure should be used for long-term storage of lambda clones in the archival collections. The phage are diluted in media containing 7% DMSO and frozen at -80 degrees C.

30 minutes

Procedure:

1. Mix 0.1 ml lambda lysate with 1ml LBM. Vortex briefly.

2. Label two sterile 2 ml cryo-vial tubes with the clone name.

3. In a hood and wearing gloves add 35 ul DMSO (dimethyl sulfoxide) to each tube.

4. Add 0.5 ml of the diluted lambda lysate to each of the DMSO- containing tubes. Vortex briefly. Store both tubes at -80 degrees C.

5. To remove phage from storage the material need not be thawed. Open the tube and scratch the surface of the frozen material with a sterile needle. Streak onto the appropriate host strain and isolate a single phage plaque for new lysate growth and subsequent use. The frozen phage stock should be recapped and returned immediately to -80 degrees C storage.

References: none