常见问题
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How are the phosphate precipitation and alkali precipitation tests conducted for bacteriological-grade agar?
Alkali Precipitation Test:
Dissolve 1.5 g of agar powder in 100 ml of purified water, adjust the pH to 8.4 ± 0.1 using NaOH. After sterilization in an autoclave at 121°C for 15 minutes, inspect the uncongealed solution in a darkroom by shining a flashlight vertically or parallel to the conical flask. The sample is considered qualified if no precipitation is observed.
Phosphate Precipitation Test:
Dissolve 1.5 g of agar powder in 100 ml of purified water, then add 0.5% K₂HPO₄. After sterilization in an autoclave at 121°C for 15 minutes, inspect the uncongealed solution in a darkroom by shining a flashlight vertically or parallel to the conical flask. The sample is considered qualified if no precipitation is observed
