Changes in serum chemical values as a result of prolonged contact with the clot

Changes in serum biochemical values as a function of serum-clot contact time were investigated. Time extending to 48 hours were studied by drawing sets of six specimens from ten subjects. Glucose, lactic dehydrogenase, the transaminases, potassium, alkaline phosphatase, and iron showed significant changes. Other common tests, including electrophoretic separations, were not affected.