Mouse RAW264 cells (ECACC catalogue number 85062803) were grown in DMEM (4.5 g/l glucose) supplemented with 10% foetal calf serum, 2 mM glutamine and penecillin/streptomycin. To induce apoptosis the cells were treated with 10 mM staurosporin for 6 h. Cytoplasmic extracts for the analysis of caspase activity were prepared as described in section ''milk analysis'' above. Protein concentrations were measured using a Bradford assay (Sigma). Caspase activity of cell extracts was measured using the Caspase-3/7-Glo assay (Promega) as recommended by the supplier. The assay provides a pro-luminescent caspase-3/7 substrate, which contains the amino acid sequence DEVD in a reagent optimised for caspase activity, luciferase activity and cell lysis. Presence of caspase 3 or 7 in the cell extract leads to cleavage of the substrate and light emission which is detected in a luminometer (Berthold). Three or more parallel samples were analysed to measure caspase activity. 50 ml of protein extract (from cells and tissues) were mixed with 25 ml of the Caspase Glo reagent and incubated at room temperature for 20 min. after which the readings were taken. Apoptosis in RAW cells was also confirmed by measuring cell viability using the Cell-Titre Blu reagent (Promega) and DNA laddering on a 2% agarose gel.