1. Normal serum, used in cultures for preparation of the streptolysin, modifies the properties of the streptolysin, causing delayed hemolysis, increased filterability, resistance to oxidation or reduction, and absence of antigenicity. 1. Streptolysin prepared without serum is an active antigen. 3. Similar temperatures are required to destroy the antigenic activity of serum-free streptolysin and...

OBJECTIVE To investigate the andropause phenomenon in Iraqi healthy subjects by evaluating serum free testosterone (FT) concentrations in association with age. METHODS This study was carried out at the Biochemistry Department, College of Medicine, University of Baghdad, between February 2012 and October 2012. This cross sectional control subject's study included 251 healthy Iraqi men with an ...