A Medium Broth

Product information

A Medium Broth from BBI is used for the cultivation and propagation of Escherichia coli.

Background

A Medium Broth is a minimal medium, on which bacteria can grow rapidly if it contains a 
carbon compound such as glucose, which serves as both a carbon source and an energy source. Salts are also present to supply nitrogen, phosphorus, and trace metals the E. coli would need during its growth cycle 1. A Medium Broth requires that 10 ml of a 20% solution of glycerol and 1 ml of 1M MgSO4 be added after autoclaving. The magnesium sulfate supplies the necessary magnesium ions that are required for DNA replication.

Formula: (Per Liter)

Ammonium Sulfate = 1.0g

Potassium Phosphate, Dibasic = 10.5g

Potassium Phosphate, Monobasic = 4.5g

Citric Acid Trisodium, Dihydrate = 0.5g

Final pH 8.0 ± 0.5 at 25 ℃

Additional supplements to be added to the broth after autoclaving:

10 ml of a 20% solution of glycerol

1 ml of a 1M MgSO4 solution

The above solutions should be sterilized separately by filtration prior to addition to the broth.

Storage

Dehydrated media should be stored in a dry area at 18-26°C.

Prepared media should be stored at 2-8°C.

Method of Preparation

• Suspend 16.5 grams of A Medium Broth powder in 1 L of purified water. Adjust pH as necessary.

• Allow the powder to dissolve. Heat and stir gently if required.

• Autoclave at 121°C for 15 minutes.

• Allow the solution to cool to 50°C or below before adding antibiotics or additional nutritional supplements

Quality Control

All powders will have a white, free-flowing homogenous appearance.

All solutions will have a clear, haze free appearance.