Quantitative determination of theophylline by an automated chemiluminescent immunoassay in serum and plasma: comparison to other methods of analysis.
A chemiluminescent immunoassay for theophylline in serum or plasma was developed for the Ciba Corning ACS: 180 automated analyzer. The assay has a limit of quantitation of 0.2 microgram/ml, with a range up to 40 micrograms/ml. The cross-reactivity to metabolites 1,3-dimethyluric acid 3-methylxanthine was 3.4% and 2.5%, respectively. Overall means of 101.0% and 97.8% were determined from dilution linearity and addition studies, respectively. When compared to a high-performance liquid chromatography (HPLC) method, a linear regression of ACS Theophylline = 0.996 (HPLC) + 0.35, r = 0.991, n = 93, was obtained. Similar results were obtained when the ACS assay was compared to other immunoassays. Precision (within-run and total coefficient of variation or CV) was < 6% in the therapeutic range (10-20 micrograms/ml). The performance data demonstrate that the ACS Theophylline assay provides an additional choice for the clinical measurement of the drug.
Malliaros
D P
DP
Ciba Corning Diagnostics Corporation, East Walpole, Massachusetts 02032, USA.
Wong
S S
SS
Wu
A H
AH
Campbell
J
J
Leonard
H
H
Houser
S
S
Berg
M
M
Gornet
T
T
Brown
C
C
Feng
Y J
YJ
D002851:Chromatography, High Pressure Liquid; D017248:Enzyme Multiplied Immunoassay Technique; D016231:Fluorescence Polarization Immunoassay / Q000379:methods; D006801:Humans; D013806:Theophylline / Q000097:blood*
D013806:Theophylline