title: High-density lipoprotein subfractions measured in stored serum.
abstract: We compared the effects of freezing serum on the determination of high-density lipoprotein (HDL) subfractions by two dual-precipitation methods, heparin and manganese chloride/dextran sulfate (HM/DS) (Gidez et al., J Lipid Res 1982;23:1206-23) and DS/DS (Warnick et al., Clin Chem 1982;28:1574), and by ultracentrifugation. Storing serum for 1 month at -70 degrees C resulted in reduced HDL3-cholesterol by ultracentrifugation and reduced total and HDL3-cholesterol by the DS/DS method. There was no change in either total HDL-cholesterol or HDL3-cholesterol with the HM/DS method. Additional studies involving only HM/DS indicated that total HDL-cholesterol in serum stored at 4 degrees C begins to decline after 3 days (-3.1 +/- 3.5%, P < 0.1). HDL was stable at -20 degrees C for 2 weeks but both total and HDL3-cholesterol decreased significantly after 1 month. Storage of serum at -70 degrees C resulted in no changes for 1 year; however, at 18 months, HDL3-cholesterol was reduced 13% (P = 0.002). We conclude that HDL subfractions can be determined accurately in serum as well as in plasma after storage at -70 degrees C for up to 1 year.
authors.affiliation: Lipid Research Laboratory, Brown University, Miriam Hospital, Providence, RI 02906.
authors.forename: L L
authors.initials: LL
authors.lastname: Bausserman
authors.forename: A L
authors.initials: AL
authors.lastname: Saritelli
authors.forename: D
authors.initials: D
authors.lastname: Milosavljevic
mesh_terms: D001793:Blood Preservation; D008076:Cholesterol, HDL / Q000097:blood*; D005260:Female; D005615:Freezing; D006801:Humans; D008297:Male; D011786:Quality Control
chemical_list: D008076:Cholesterol, HDL