Validation of a radioimmunoassay for the determination of human plasma concentrations of lamotrigine.
A precise and sensitive radioimmunoassay to determine human plasma lamotrigine (430C78), Lamictal) is described. The method is a direct double antibody procedure employing a rabbit polyclonal first antibody raised to a BSA conjugate of lamotrigine, and an iodinated tyrosine methyl ester of lamotrigine as the tracer. Both reagents are added simultaneously to samples containing lamotrigine prior to an overnight incubation at 4 degrees C. The method has a sensitivity of 20 ng ml-1, when plasma samples are initially diluted 1:20 with phosphate buffer and sample volumes of 20 microliters are used. The intra-assay precision at 40, 80 and 160 ng ml-1 was 6.2, 2.1 and 4.8%, respectively, and the inter-assay precision at 500, 2000, 5000 and 10,000 ng ml-1 was 4.6, 5.7, 4.6 and 5.9%, respectively. The method was specific and showed reasonable correlation with an HPLC method [1].
Biddlecombe
R A
RA
Department of Bioanalytical Sciences, Wellcome Research Laboratories, Beckenham, Kent, UK.
Dean
K L
KL
Smith
C D
CD
Jeal
S C
SC
D000918:Antibody Specificity; D000927:Anticonvulsants / Q000097:blood*; D002021:Buffers; D006433:Hemocyanins / Q000276:immunology; D006801:Humans; D007457:Iodine Radioisotopes; D000077213:Lamotrigine; D011786:Quality Control; D011863:Radioimmunoassay; D012015:Reference Standards; D012710:Serum Albumin, Bovine / Q000276:immunology; D014227:Triazines / Q000097:blood*
D000927:Anticonvulsants; D002021:Buffers; D007457:Iodine Radioisotopes; D014227:Triazines; D012710:Serum Albumin, Bovine; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D000077213:Lamotrigine