Ans. a. Semen In sexual offences, a preliminary examination under filtered ultraviolet light can be made. Stains of urine, vaginal discharge and seminal fluid show a bright fluorescence. The fluorescence of seminal stains is of a bluish-white colour and such stains are selected for fuher examinations. Examination of Seminal Stains Physical Examination: A preliminary examination under filtered ultraviolet lightQ can be made. Stains of urine, vaginal discharge and seminal fluid show a bright fluorescence. The fluorescence of seminal stains is of a bluish-white colour and such stains are selected for fuher examinationsQ Chemical Examination: Mnemonic - 'create A F B' Creatine Phosphokinase testQ: Depends on presence of CPKdeg in semen Acid Phosphatase testQ: Depends on presence of acid phosphatase in semen Florence testQ: Depends on presence of CholineQ in semen. Barberio's testQ: Depends on presence of SperminQ in semen Microscopic examination Involves identification of spermatozoa under microscope. Fluorescence microscopy is based on the principle that the Y-chromosome is fluorescence to quinacrinedeg. Electrophoretic Methods: Acid-Phosphatase TestQ LDH Isoenzyme TestQ