Bacte LAB agar storage Flashcards
A. Storage of Prepared Media
▪ Store agar plates _____________ and __________in ______________ or a ____________________
refrigerated, inverted, plastic bags, sealed
container
Agar with dyes should be protected from light and discarded when ____________________
color changes
Presence of condensate – place plates in __________(temp) incubator briefly
35-27C
For test tube/bottle media
- Tighten cap before __________
- Mark liquid level in tubes (_____(percent) of each batch) after sterilization and monitor liquid loss for >____________ ; if the loss is 10% or more discard the batch
storage, 10%, 2 weeks
Petri dish with solid media
Discard if stored for _________
Discard if they are ____________ (wrinkled, cracked, pitted)
_______the batch if growth or false positive responses are observed before use
more than 2 weeks, dried out, Reject
Broth in screw-cap flask
2-8C
96 h
Poured agar in plates with tight-fitting covers
2-8C
2 weeks
Agar or broth in loose-cap tubes
2-8C
2 weeks
Agar or broth in tightly closed screw-cap tubes
<30C
3 months
Poured agar plates with loose-fitting covers in sealed
plastic bags
2-8C
2 weeks
Large volume of agar in tightly closed screw-cap flask or bottle
2-8C
3 months
Excess heat, pH too low causing acid hydrolysis, inaccurate weighing, inadequate mixing, agar not dissolved, poor quality of agar in dehydrated culture media.
Soft Gel
Contaminated glassware, impure water, overheating, chemical contamination, pH taken at wrong temperature, pH measuring equipment faulty or poorly standardized, deterioration of dehydrated medium.
pH not correct
Impure water, dirty glassware, deterioration of dehydrated medium,
excess heat, pH incorrect.
Abnormal Color
Excess heat, deterioration of dehydrated medium, impure water or glassware.
Precipitation
