Stability of twenty-five analytes in human serum at 22 degrees C, 4 degrees C, and -20 degrees C

The stability of 25 analytes from serum of healthy donors was determined at room temperature, 4 degrees C, and -20 degrees C over 48 h, 14 days, and 4 months, respectively. Glucose, blood urea nitrogen, sodium, potassium, chloride, creatinine, calcium, phosphorus, uric acid, total protein, albumin, triglycerides, lipase, total creatine kinase, gamma-glutamyltransferase, iron, magnesium, and cholesterol were stable at all three temperatures for the specified times. Carbon dioxide, aspartate and alanine aminotransferases, lactate dehydrogenase, amylase, alkaline phosphatase, and high-density lipoprotein cholesterol demonstrated some loss over time. Proper storage temperatures and times must be considered for these analytes if measurement is not to take place immediately after specimen collection.