TWENTY-THIRD ANNUAL EASTERN FISH HEALTH WORKSHOP JOHN CARVER INN, PLYMOUTH, MA 30 MARCH - 2 APRIL, 1998 Plasma And Serum Chemistry Values In Four Species Of Fish: Trout, Catfish, Tilapia, And Hybrid Striped Bass. Terry C. Hrubec and Stephen A. Smith Department of Biomedical Science and Pathobiology, VA-MD Regional College of Veterinary Medicine, Virginia Tech, Blacksburg VA 24061. Blood chemistry analytes are often determined for fish using either serum or plasma samples. Serum is prepared by clotting the blood and then centrifuging to separate the fluid component from the blood cells and clotting factors. Plasma is prepared from blood treated with an anticoagulant, traditionally heparin. The anticoagulated blood is centrifuged shortly after collection to separate the fluid component from the blood cells. Theoretically, plasma and serum are similar except for the clotting factors present in plasma. This study was conducted to determine if there were any notable differences between blood analytes when measured from plasma or serum. Ten individuals from four species, Channel catfish (Ictalurus punctatus), Rainbow trout (Oncorhynchus mykiss), Tilapia (Oreochromis hybrid) and Hybrid striped bass (Morone saxatilis X Morone chrysops) were used in this study. The fish were anesthetized in MS-222 and a single blood sample collected from each fish. The blood from each fish was divided into a serum blood tube held at room temperature and a heparinized blood tube kept on ice. The serum tube clotted at room temperature for 1 hour and was then centrifuged and the serum collected. Plasma tubes were centrifuged immediately and the plasma removed. The blood was analyzed for the following standard biochemical analytes: total protein, albumin, globulin, creatinine, total bilirubin, alkaline phosphatase, aspartate aminotransferase, sodium, potassium, chloride, calcium magnesium, phosphorus, glucose and cholesterol. For all species, values for potassium were lower while magnesium and phosphorus values were higher in the serum compared to the plasma. Glucose values were lower in the serum for trout and hybrid striped bass but not in the other two species. The differences between serum and plasma most likely represent sample degradation and biochemical changes in analyte levels while the blood is clotting during serum preparation.   Return to 23rd Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page