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 Jaques 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 medium1 x 5ml bottle of 5% glucose solution1 x 5ml bottle of 5% lactose solution1 x 5ml bottle of glucose & lactose solution0.3g O-NPG (O-nitrophenyl-beta-D-galactopyranoside)1 x E-Coli cultureAdditional materials required (not included):Test tubes (3 per student)4 x pipettesAccess to a 37°C water bath or incubator