Michael B Switzer

US Patent:

7482165, Jan 27, 2009

Filed:

Aug 24, 2005

Appl. No.:

11/210346

Inventors:

Min Zheng - Pembroke Pines FL, US
Jing Li - Miami FL, US
Yi Li - Miami FL, US
Michael J. Switzer - Coral Springs FL, US

Assignee:

Beckman Coulter, Inc. - Fullerton CA

International Classification:

G01N 33/48

US Classification:

436 63, 436 8, 436 10, 436 17, 436 70, 436174, 436175, 435 2, 422 73

Abstract:

Methods of prevention and correction of white blood cell interferences to the measurements of mean cell volume (MCV), red blood cell concentration (RBC) and hematocrit (Hct) of a blood sample are disclosed. The interference to MCV can be prevented by identifying a valley between the red blood cell and white blood cell modes on the red blood cell distribution histogram, defining a red blood cell region using the valley and calculating MCV within the defined region. Alternatively, a curve fit of the white blood cell population on the red blood cell distribution histogram can be used to exclude the white blood cells. RBC can be corrected by subtracting the white blood cell concentration obtained from the analysis of a second aliquot sample, when the white blood cell concentration (WBC) exceeds a predetermined criterion. Hct of the blood sample can be calculated using the obtained MCV and RBC.