Journal of Lipid Research, Vol 23, 1236-1242, Copyright © 1982 by Lipid Research, Inc.

ARTICLES

Determination of high density lipoprotein-cholesterol in human plasma stored at -70 degrees C

PS Bachorik, RE Walker and PO Kwiterovich Jr

We determined the effect of storage at -70 degrees C on the determination of plasma high density lipoprotein (HDL)-cholesterol. Plasma from 106 subjects was stored for 1, 6, and 12 months, then treated with heparin and MnCl2 to remove other lipoproteins, and HDL- cholesterol was measured. The mean HDL-cholesterol level decreased by 2.9% after 1 month, and by 5.1% after 12 months. The magnitude and direction of the changes were not constant, but were correlated primarily with HDL-cholesterol concentration. After 1 month, samples with HDL-cholesterol levels below 40 mg/dl tended to increase, and those above this value tended to decrease. By 12 months, only those samples with HDL-cholesterol below 22 mg/dl tended to increase. Linear regression analysis indicated changes of 0.9-1.5 mg/dl for each 10 mg/dl initial HDL-cholesterol concentration. Storage of heparin-MnCl2 supernatants, rather than unfractionated plasma, minimized these changes. The mean HDL-cholesterol of stored heparin-MnCl2 supernatants was 3.3% lower after 12 months, and the change was constant regardless of lipoprotein concentration. The findings suggest the possible occurrence of changes in the heparin-MnCl2 precipitability of lipoproteins during storage, which produce errors in HDL-cholesterol analyses, and indicate that samples can be stored more satisfactorily if the other lipoproteins are removed first.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. R. Warnick, M. Nauck, and N. Rifai Evolution of Methods for Measurement of HDL-Cholesterol: From Ultracentrifugation to Homogeneous Assays Clin. Chem., September 1, 2001; 47(9): 1579 - 1596. [Abstract] [Full Text] [PDF]

				W. J. Shih, P. S. Bachorik, J. A. Haga, G. L. Myers, and E. A. Stein Estimating the Long-Term Effects of Storage at -70 {degrees}C on Cholesterol, Triglyceride, and HDL-Cholesterol Measurements in Stored Sera Clin. Chem., March 1, 2000; 46(3): 351 - 364. [Abstract] [Full Text] [PDF]