title: Storage of serum or whole blood samples? Effects of time and temperature on 22 serum analytes.
abstract: Information on the stability of serum analytes during storage of serum or whole blood samples is often incomplete and sometimes contradictory. Using a widely available analyser (Hitachi 737/Boehringer), we therefore determined the effects of storage time and temperature on the measured concentrations of the following serum analytes: sodium, potassium, calcium, chloride, inorganic phosphate, magnesium, creatinine, urea, uric acid, bilirubin, cholesterol, HDL- and LDL-cholesterol, triacylglycerols, creatine kinase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, alpha-amylase, lactate dehydrogenase and cholinesterase. When separated serum was stored at + 9 degrees C for seven days, the mean changes in inorganic phosphate and lactate dehydrogenase exceeded significantly (p < 0.05 or 0.001, respectively) the maximum allowable inaccuracy according to the Guidelines of the German Federal Medical Council; all other quantities were sufficiently stable. In serum at room temperature, inorganic phosphate, uric acid, HDL-cholesterol and triacylglycerols increased continuously, whereas bilirubin, LDL-cholesterol, creatine kinase and aspartate aminotransferase decreased more than the guidelines permit during the storage period (p < 0.05 for aspartate aminotransferase, p < 0.001 for the other analytes mentioned). In whole blood stored for 7 days at + 9 degrees C, only the following serum analytes satisfied the stability requirements of the guidelines: calcium, urea, cholesterol, HDL-cholesterol, LDL-cholesterol, triacylglycerols, creatine kinase, gamma-glutamyltransferase and cholinesterase. When stored at room temperature, only sodium, uric acid, bilirubin, cholesterol, triacylglycerols, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, alpha-amylase and cholinesterase were still stable after 3 days. The data collected show that all quantities examined are sufficiently stable for four days in separated serum stored at + 9 degrees C.
authors.affiliation: Institut für Klinische Chemie und Laboratoriumsdiagnostik der Heinrich-Heine-Universität Düsseldorf, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Heins
authors.forename: W
authors.initials: W
authors.lastname: Heil
authors.forename: W
authors.initials: W
authors.lastname: Withold
mesh_terms: D001774:Blood Chemical Analysis; D001793:Blood Preservation; D004573:Electrolytes / Q000097:blood; D004798:Enzymes / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007202:Indicators and Reagents; D008055:Lipids / Q000097:blood; D012016:Reference Values; D013696:Temperature; D013997:Time Factors
chemical_list: D004573:Electrolytes; D004798:Enzymes; D006454:Hemoglobins; D007202:Indicators and Reagents; D008055:Lipids