Repeated samples of fat obtained with a biopsy needle.

Introduction The established and large-scale use of certain synthetic chemicals, especially pesticides, has led to their absorption and deposition in animals and man. The authors' interest lay in the pharmacodynamics of the synthetic organochlorine insecticide, dieldrin, which is primarily deposited and stored in the body lipid. Its study required repeated measurements of the deposition of this compound in the adipose tissue of volunteer subjects deliberately ingesting dieldrin, and in a random selection of the general population fortuitously exposed to dieldrin (and similar compounds) in an average normal diet. Open surgical biopsy of subcutaneous adipose tissue entails local scarring and discomfort, and so recourse was made to needle biopsy.