Beckman Coulter COULTER LH 750 System, Reference, Page: 48 / 120

PN 4277248DD
3-16
OPERATION PRINCIPLES
PARAMETERS AND THEIR DERIVATION
Mean Corpuscular Volume (MCV)
MCV is the average volume of individual erythrocytes derived from the RBC histogram. The
system multiplies the number of RBCs in each channel by the size of the RBCs in that
channel. The products of each channel between 36 fL and 360 fL are added. This sum is
divided by the total number of RBCs between 36 fL and 360 fL. The analyzer then multiplies
by a calibration constant and expresses MCV in femtoliters.
Hematocrit (Hct)
Hct is the relative volume of packed erythrocytes to whole blood, computed by the formula:
HCT (%)= (RBC x MCV) / 10
Mean Corpuscular Hemoglobin (MCH)
MCH is the weight of hemoglobin in the average erythrocyte, computed by the formula:
MCH (pg) = (HGB/RBC) x 10
Mean Corpuscular Hemoglobin Concentration (MCHC)
MCHC is the average weight of hemoglobin in a measured dilution, computed by the
formula:
MCHC (g/dL) = (HGB/HCT) x 100
Red Cell Distribution Width (RDW)
RDW is the size distribution spread of the erythrocyte population derived from the RBC
histogram. Expressed as coefficient of variation (CV) %.
Platelet (Plt) Count
Plt is the number of thrombocytes derived from the Plt histogram and multiplied by a
calibration factor. This number is expressed as:
Mean Platelet Volume (MPV)
MPV is the average volume of individual platelets derived from the Plt histogram. It
represents the mean volume of the Plt population under the fitted Plt curve multiplied by a
calibration factor. This number is expressed in femtoliters.
NRBC % (Nucleated Red Blood Cells)
NRBC enumeration is achieved through the combined use of VCS technology along with an
advanced algorithm applied to the WBC count. NRBC% is defined as the number of nucleated
red blood cells per 100 WBC.
PLT = n 103 × cells / L µ