SYSMEX XE-5000, Инструкция по эксплуатации, Страница: 231 / 262

CHAPTER 11 Technical Information
Sysmex XE-5000 Instructions for Use 11-13
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(2) Lateral fluorescent light
When light is emitted to fluorescent material, such as stained
blood cells, light of longer wavelength than the original light is
produced. The intensity of the fluorescent light proportionally
increases with the concentration of the precipitated stain in
the blood cells. The intensity of the emitted fluorescent light
indicates the degree of blood cell staining and as such the
RNA and/or DNA concentration.
Fluorescent light is emitted in all directions; the XE-5000
detects the fluorescent light that is emitted sideways.
SLS-Hemoglobin method
In the past, the mainstream methods for automatically
measuring hemoglobin were the cyanmethemoglobin method
and oxyhemoglobin method. But these methods have both
advantages and disadvantages when they are used with a
large, fully automatic instrument such as the XE-5000.
The cyanmethemoglobin method was recommended by the
International Committee for Standardization in Haematology
(ICSH) in 1966 as an international standard method. But
since its hemoglobin conversion speed is slow and
multiple-sample processing is an assumed requirement, this
method is not really appropriate for automatic analysis.
Moreover, since it uses cyanide compounds, which are
poisonous as reagents, the liquid waste must be treated,
making the method undesirable from an environmental
perspective.
Currently, this is not an appropriate analysis method,
particularly as a large fully automatic instrument that
discharges large amounts of liquid waste.
In contrast, the hemoglobin conversion speed of the
oxyhemoglobin method is fast, as blood hemoglobin is
instantly converted into oxyhemoglobin. And since it does not
use poisonous substances such as cyanide, it is a suitable
method for performing automatic analysis. It cannot, however,
convert methemoglobin into oxyhemoglobin, which is not a
problem for normal human blood, but will result in values that
are lower than the true values for samples that contain large
amounts of methemoglobin, such as control blood samples.
The SLS-hemoglobin method is an analysis method that
makes use of the advantages of the two aforementioned
methods.
As with the oxyhemoglobin method, the hemoglobin
conversion speed of the SLS-hemoglobin method is fast and
the method does not use poisonous substances, making it a
suitable method for automation.
Further, since methemoglobin can be analyzed, control
samples such as blood containing methemoglobin can also
be accurately analyzed.