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Prep Room Quality Control

This room is completely isolated from all plant-growing areas (greenhouse and growth room). Unsterilized soil is prohibited both in this room (or in any room except culture storage). Field soils are stored in a separate greenhouse across the street from our building, and it is there that they are sterilized before being moved to any of the rooms pictured here.

Select any room to see procedures used in that location.

  Lab   Growth

Prepping samples by sinkExcept for the various types of pots used daily to set up cultures, stored materials are kept in boxes or other labelled containers. All of the pots, collars, and racks are prewashed before storing.

Floors are washed at least weekly; no sweeping is allowed as it is likely to raise dust. Tables and shelves are cleaned with a wet sponge or towel (no dusting).

One refrigerator is placed in this room, where solutions associated with processing of cultures (sucrose, azide, buffers), seeds, and inocula for culture setup (transferred from long-term storage areas) are kept.

Closed storage containersAll steam-sterilized growth media are stored in closed containers and used as needed. Steamed sand-soil mixes are stored at least two weeks before using, during which time they are dried and rewetted at least twice. This step allows time for manganese and other minor elements solubilized by steam heat treatment to be readsorbed to soil particles. Failure to do this sometimes leads to toxicity symptoms (marginal necrosis), especially with legume seedlings.

Large container for sterilizing potsPots, deepots, and cone-tainers are surface-sterilized in 10% chlorox for a minimum of one hour. After rinsing and drying, they are handled only with gloves and stored in presterilized plastic bins.

Paper (usually unused newsprint obtained in large rolls) is laid on all work surfaces and disposed of immediately after completion of an operation. At no time do pots or other presterilized items touch table or bench surfaces.