Category Archives: Daily Q&A

Lab Protocol #1: Making Agar Plate, LB Broth

Making Agar Plate
20g LB Broth
1L H2O
15g Bacto Agar
Mix well first. Pour the mixture into a 2L flask.

Some bacto agar will not be completely dissolved. Therefore, you can always let the bacto agar to settle in your 2L flask, then take the top phase of liquid to flush the remaining bacto agar out.

After that, put it into autoclave machine (wet cycle: this is often preset. But usually it is 100C for 20-30 minutes)

If you wish to make plates for penicillin, wait until the flask to cool down a bit, don’t wait for too long, otherwise the agar will solidify (if you can bear the temperature with your bare skin, the temperature is good). At this time, add penicillin at 1:1000 dilution.

Making LB Broth

40 g LB Broth

2L H2O

Mix well, pour into 4 glass bottles, then autoclave

*When autoclaving liquid in glass bottles, make sure to not tighten the glass bottle completely.