Not every cell in the body is alike. Genes may be switched 'on' or 'off' in different cells so that a muscle cell, for instance, is different from an epidermal cell. This kit examines the mechanism by which a particular gene in the bacterium Escherichia Coli, coding for the enzyme b-galactosidase, is turned 'on' in the presence of lactose. This is the gene studied in the 1950's and 60's by Jacques Monod and François Jacob and led to the generally accepted Jacob-Monod model of gene regulation.

The kit is an ideal introduction to this complex subject at 'A' level & contains enough material for twenty students.

The kit contains:

• 3 x 50ml bottles of minimal medium
• 1 x 5ml bottle of 5% glucose solution
• 1 x 5ml bottle of 5% lactose solution
• 1 x 5ml bottle of glucose & lactose solution
• 0.3g O-NPG (O-nitrophenyl-beta-D-galactopyranoside)
• 1 x E-Coli culture

Additional materials required (not included):

• Test tubes (3 per student)
• 4 x pipettes
• Access to a 37°C water bath or incubator