PROPRIETARY INFORMATION
CONFIDENTIAL MATERIAL
Not for Customer Distribution
Assays/Reagents
AEROSET
®
System Troubleshooting Guide
167
94816-107—November 2004
Total Bilirubin
Observed Problem
Total Protein
Interference Information
Dextran has been reported to negatively interfere with the
Abbott Clinical Chemistry Total Protein assay, a biuret
method.
The following summary is from the
Methods in Clinical
Chemistry, 1987
, by Laurence A. Kaplan.
“Low molecular weight dextrans interfere with the biuret
assay. The dextrans, used as plasma volume expanders for the
treatment of low blood pressure, complex with copper and
tartrate in the reaction mixture and form a precipitate. The
degree of the resulting interference varies greatly with the
concentration of dextran and the composition of the biuret
reagent. The percent interference can range from 3% to 5% at
usually encountered dextran levels. Although the interference
is usually a positive one, a negative interference was reported
for the bichromatic DuPont ACA procedure.”
Direct Bilirubin result exceeds Total Bilirubin result
Probable Cause(s)
Corrective Action(s)
Total bilirubin concentration of
0.2 mg/dL (3.4 µmol/L) or less;
observed when nearly all reacting
bilirubin is direct bilirubin.
For information only. In this situation,
individual laboratories should establish
reporting guidelines.
Hemolyzed sample.
Obtain a new sample.