PROPRIETARY INFORMATION
CONFIDENTIAL MATERIAL
Not for Customer Distribution
Assays/Reagents
AEROSET
®
System Troubleshooting Guide
127
94816-107—November 2004
Sample Carryover
No sample carryover effects were observed when testing
samples with high digoxin concentration (4.0 to 5.0 ng/mL)
immediately before samples with low digoxin concentration
(0.3 to 0.8 ng/mL).
Frequently Asked Questions (FAQ)
Question
Response
MULTIGENT
®
Digoxin results do not match
another method. Why?
MULTIGENT Digoxin is a competitive
binding method, in which lowest levels of
digoxin concentration produce highest signal
levels. In addition, the reading wavelength of
700 nm minimizes interference from HAMA
(human anti-mouse antibodies), hemolysis,
bilirubin, and lipemia. The disagreement
between methods may be due to cross
reactivity and interference differences.
Which controls are recommended? Which
controls have AEROSET assay values?
Bio-Rad Liquichek TDM control has been used
successfully with this method, although
system-specific assay values are not provided
in the package insert. Onboard stability and
20 day precision testing were done with this
product.
Why am I getting negative calibration rates?
Is this normal?
This is normal. The competitive binding
method provides a curve in which the signal
is inversely proportional to concentration,
i.e
., low sample values produce the highest
rates. The zero calibrator rate (highest rate) is
used as a blank and is subtracted from the
rates of all other calibrators, causing them to
be negative.
How does this assay perform with DLIS
(digoxin-like immunoreactive substances)?
Refer to the Interfering Substances section of
the Digoxin package insert.