PROPRIETARY INFORMATION
CONFIDENTIAL MATERIAL
Assays/Reagents
Not for Customer Distribution
142
AEROSET
®
System Troubleshooting Guide
94816-107—November 2004
The Reaction Mode for HbA
1c
is listed as RATE
UP in the package insert. Why does the
Reaction Graph appear to show an END
DOWN reaction?
• The reaction is defined as RATE UP because
the change in absorbance per minute
increases over time as agglutination occurs
in the main read window.
• The appearance of the Reaction Graph is
because the assay is based on competitive
inhibition. When there is a small amount
of HbA
1c
in the sample, the HbA
1c
hapten
(agglutinator) in the R2 reagent binds with
the HbA
1c
antibody-coated microparticles
in the R1 reagent. The resultant
agglutination causes increased absorbance.
• When HbA
1c
concentration in the sample
is high, there is less agglutination because
there are fewer binding sites available for
the agglutinator. This results in a lower
absorbance change over time.
Does Abbott have microcentrifuge tubes?
Abbott TDx
®
centrifuge tubes, LN 9527-40
can be ordered. There are 100 tubes per box.
There is no sample probe SmartWash™ in
assay configuration. Was hemolysate build-up
on the sample probe an issue during assay
testing?
Studies were run on assays most sensitive to
hemolysis, and there was no evidence of
hemoglobin interference. Also, calculations
were done based on maximum sample probe
carryover and the worst case of carryover was
lower than hemoglobin interference claims
for the assays most sensitive to it.
Why are four reagent cartridges provided for
THb, and only two cartridges provided for
HbA
1c
?
Reagent volume requirements are 200 µL for
THb and 100 µL for HbA
1c
.
Besides MULTIGENT
®
HbA
1c
controls, have
other vendor controls from been tested?
No.
Was sodium fluoride tested as an
anticoagulant for the HbA
1c
assay?
No.
Frequently Asked Questions (FAQ) (Continued)
Question
Response