Bacterial media recipes

TB (Terrific Broth)

The following recipe can be directly autoclaved in Erlenmeyer flasks if desired.

  1. Combine and autoclave the following components. The final 10% volume will be added afterwards.

Ingredient

Amount per 1L final volume

Tryptone

12 g

Yeast extract

24 g

Glycerol

4 mL

Deionized water

900 mL

  1. After the mixture has cooled, add 100 mL / liter final volume of 10x TB salts and desired antibiotics.

10x TB salts

The potassium phosphate salt solution acts as a pH buffer. It must be autoclaved separately to prevent high-temperature reactions between the salts and other components of TB.

  1. Combine the following, filling to the desired final volume with deionized water.

Ingredient

Target concentration

Amount per 1L final volume

KH2PO4

0.17 M

23.1 g

K2HPO4

0.72 M

125.4 g

Note

Because we are making a fairly concentrated solution, you will need to add less than the total final volume of water (e.g. for a liter of TB salts, you may only have to add 900 mL water).

I tend to add 70% of the water, wait until all of the salt dissolves, then fill up to the relevant line on the flask. This doesn’t have to be super precise.

  1. Autoclave the salt solution.

SOC Media

Note

We use 2x concentrated SOC for better bacterial growth. This is reflected in the amounts below.

  1. Combine 62 g of SOC powder with deionized water to a final volume of 1 L.

  2. Autoclave and let cool.

LB Media

  1. Resuspend 25 g of LB Broth powder with deionized water to a final volume of 1 L.

  2. Autoclave and let cool.