Abaxis VetScan HM5, Operator'S Manual

Page: 132 / 164

B-6 Operating Principles
B.3 Hemoglobin Determination
Hemoglobin is measured directly by means of the traditionally used cyanomethoglobin reaction, but
the HM5 uses cyanide-free substances to reach the same endpoint.
Hemoglobin concentration is measured photometrically.
B.3.1 Hemoglobin Determination by Photometry
HGB determination is one of the most important hematology parameters, as it relates to the oxygen
carrying capacity of blood.
The analyzer uses cyanide-free lysing reagents to minimize negative effects on user safety and the
environment. The effect of cyanide-free Lyse is very similar to that of Lyse containing cyanide, but the
chemical reaction is slightly different. The figure below illustrates the HGB measurement method.
HGB is measured by passing light (540 nm)
through the WBC dilution, and measuring
the transmitted light with a photo detector.
The light intensity (I) of the sample liquid is
logarithmically proportional to the
concentration of HGB:
HGB

log (I
reference
/ I
sample
)
Light source
(lamp)
540 nm
filter
Sample
dilution
Photo
detector