Prepare a homogenate of a biological tissue, liver. Dissect out the liver from an albino rat, dry it, folding between folds of filter paper sheets, and drop it in a beaker kept in ice. Using a pair of scissors, mince it into small pieces. Add about 10 ml of cold distilled water to the mince, transfer to a homogeniser, and grind well. The operation should be carried out in cold, and frothing should be avoided. The homogenate so obtained is filtered through two to three layers of muslin to remove any lumps that may be present. The filtrate is diluted to 20 ml and stored in cold. This homogenate is kept for use in all experiments. Determine the protein content of the various fractions (O–E) by any suitable method, preferably by the modified Biuret method.