c. Sample
Samples are checked for physical interference. The analyzer estimates the sample indi-
ces, hemolysis, lipemia, and icterus using absorbance readings for the sample at 340 nm,
405 nm, and 467 nm. This information is then compared to pre-established hemolysis,
lipemia, and icterus limits for each method. When all three indices are below these limits
for the method, that method's results are printed. When any index exceeds the limit, the
result is suppressed and the error condition displayed as HEM, LIP, or ICT.
7.3
Running Controls
A control is a biological sample or solution with a suitably contrived matrix that is analyzed for pur-
poses of quality control. The composition of the matrix must be such that the solution closely matches
that of the biological specimen for characteristics of importance to the analyzer. Control materials need
to be stable and available in sufficient volumes in multiple portions and over an extended period. Many
control products are available commercially. Assayed controls also come with expected values of the
analytes for guidance.
The VS2 includes an extensive iQC program that eliminates the need for routine external liquid con-
trols. If an external control is needed occasionally, the analyzer provides a memory bank to store that
data. The control must have a composition closely matching that of the biological specimen in charac-
teristics important to analysis. Control materials must be available in sufficient volumes and multiple
portions, and stable over an extended period. Many control products are available commercially.
Assayed controls also include expected analytes values for guidance.
The Run Controls menu function automatically stores control results in a memory separate from the
patient results memory. The Recall function may be used to search for specific control results without
searching through all patient results stored in memory.
Note:
Before a control can be run, a control level must be enabled in the reference ranges —
see
page
Controls can be run whenever the analyzer displays the Home screen.
Note:
Always wear personal protective equipment (gloves, safety glasses, lab coat) when run-
ning any control containing components derived from human sources. The gloves should
be powder free to avoid getting powder on the analyzer optics.
For more details on running an analysis, see
5-6.
Calibration and Quality Control
"Running Tests" on page
4-4.
7-3