Positive interference of merthiolate in the TDx digoxin assay in control samples used in the Belgian External Quality Assessment (EQA) Scheme.
We investigated the possible origin of the spuriously high results observed with the Abbott TDx Immunoassay in the 1991 Belgian external quality assessment scheme for digoxin. The present work ascribes this discrepancy to a matrix effect induced by the addition of merthiolate as preservative to the control samples. It consequently stresses the importance of avoiding the use of this compound for preparing such samples.
Devleeschouwer
N
N
Department of Clinical Biology, Institut of Hygiene and Epidemiology, Brussels, Belgium.
Libeer
J C
JC
Schiettecatte
J
J
Maes
V
V
Demolder
J
J
Debusschere
P M
PM
Gorus
F
F
D004077:Digoxin / Q000097:blood*; D005189:False Positive Reactions; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D011374:Progesterone / Q000097:blood; D011786:Quality Control; D011863:Radioimmunoassay; D011933:Reagent Kits, Diagnostic; D013849:Thimerosal / Q000097:blood*
D011933:Reagent Kits, Diagnostic; D013849:Thimerosal; D011374:Progesterone; D004077:Digoxin; D006854:Hydrocortisone