Petri Dish To Petri Dish or Liquid Culture

Petri Dish To Petri Dish or Liquid Culture


      All work should be conducted on a sterile surface in front of a HEPA-filter sterile air source.  Read Stamets "The Mushroom Cultivator" or "Growing Gourmet and Medicinal Mushrooms" for details on sterile culture technique.

      o) Prepare potato water or malt extract agar petri dishes or liquid cultures using our recipes (link) or purchase petri dishes to inoculate (link)

      i) Sterilize all reused tools in autoclave(pressure cooker) when possible.  Wash hands and arms before starting.  Use a surgical mask and gloves while working.  Rub hands down with 70 % IPA every 5 minutes or so.  Remember not to use lighter while you still have IPA on hands!

      ii) Clean work area with 70 % IPA.  Wait until IPA fumes dissipate before using ignition source (torch, alcohol lamp, or bacti-cinerator)

      iii) Arrange source culture and culture medium to be inoculated on working area;  partially open any lids/remove parafilm so that rest of work can proceed swiftly.  Only partially open the cultures you plan to use with one source culture at a time (2-5 petri dishes and/or 1-3 liquid cultures per petri dish with one sterilization of scalpel)

      iv) Sterilize scalpel/inoculating loop with heat source.  Keep IPA away!  Invisible IPA fumes may explode/ignite!  Be sure to have read the MSDS for IPA and follow safety precautions.

      v) Cool scalpel in one of the containers of fresh sterile medium to be inoculated.  Cut a tiny triangle from the agar of the colonized petri dish.  Ascetically transfer to fresh petri dish.  With graceful fast technique it is possible to do a few transfers before re-sterilizing the scalpel.  As soon as you set the scalpel down to sterilize again seal any completed containers.  To prevent contamination over longer term wrap with a thin strip of parafilm.

      vi) You can repeat iv-v several times to get more transfers, but the more the source petri dish is exposed the higher the chance of introducing contamination.

      vii) Incubate at correct temperature for species (link to species list/instructions)