Pouring plates

1. Prepare the media

Prepare 1 liter of LB agar. Use a 2 liter flask and add 1 l of distilled water from the DW tap at the sink. Add 32 g of LB agar and a large stir bar. Swirl to dissolve. Cover the flask with aluminum foil and use autoclave tape to mark the foil.

2. Autoclave

Run a 15 min liquid cycle. Safety Note: Open the autoclave door slowly to avoid burns from the release of steam.

3. Cool media to 50 C

Put the media in the 65C water bath till it is cool enough to hold. Mix the media on a large stir plate to avoid density gradients where the top is more aqueous (which will make runny plates) and the bottom is more agar like (making plates which set up too quickly).

4. Add the antibiotic

Safety Note: Most antibiotics are considered hazardous chemicals. Always wear gloves when handling antibiotic solutions and weigh powders out in the chemical hood. For Ampicillin plates, add ampicillin to a concentration of 50 ug / ml. The ampicillin is mixed up ahead in water and filter sterilized. For 100 mg/ml AMP add 0.5 ml.

5. Pour the plates

Use 4" plates. Wipe down a lab bench. Pour plates to a depth of 3 to 5 mm and cover. Typically you get about 40 plates per 1 l batch. Let plates set until cool. Mark plates with colored marker (Blue=LB Red=Amp Green=Chloramphenical

6. Store the plates in refridgerator.

Stack the plates back into the original bags. Store the plates upside down in the fridge or cold room until needed.