Hanh L Onishi

US Patent:

61975923, Mar 6, 2001

Filed:

Jul 15, 1999

Appl. No.:

9/353977

Inventors:

Thomas H. Duffy - Santa Ana CA
Hanh Onishi - Irvine CA

Assignee:

Bio-Rad Laboratories, Inc. - Hercules CA

International Classification:

G01N 3100

US Classification:

436 8

Abstract:

Control materials containing specified concentrations of the osteoporosis markers deoxypyridinoline, pyridinoline, C-telopeptide and N-telopeptide in a matrix that is substantially the same as that of human urine are prepared by selecting amounts of human urine that contain sufficient quantities of the markers to achieve the target levels upon concentration, lyophilizing the selected urine, optionally after clarification by filtering, freezing and thawing, and pH adjustments, then reconstituting the lyophilized material, and combining and/or diluting the lyophilized material, either before or after reconstitution, to adjust the marker contents to the target levels. Surprisingly, the markers survive this process sufficiently intact to serve as reliable control materials of known composition and concentration.