Selection of high-affinity and high-specificity monoclonal antibodies for 1 alpha,25-dihydroxyvitamin D.
The preparation of high-affinity and high-specificity monoclonal antibodies to 1 alpha,25-dihydroxyvitamin D is described. Monoclonal antibodies were derived from Balb-c mice immunised with either 1 alpha-hydroxy-25,26,27-trinor-24-cholecalcioic acid or with 1 alpha-hydroxy-26,27-dinor-cholecalciferol-25-oxime, and spleen cells were hybridised with mouse myeloma cells. From six fusions nine monoclonal antibodies (MAb's) were selected from 676 antibody-secreting hybrids. Antibodies varied widely in their ability to bind 1 alpha,25-dihydroxyvitamin D3 (50% displacement of radioligand ranged from 25 - 900 pg); two had particularly useful characteristics for 1 alpha,25-dihydroxyvitamin D assay. MAb 5F2 has high affinity (Ka = 1.39 X 10(10) M-1) and does not discriminate between 1 alpha,25-dihydroxyvitamin D2 and D3, thus enabling the two forms to be measured together. MAb 1G7 is highly specific, having no cross-reactivity with 25-hydroxy-, 24,25-dihydroxy- or 25,26-dihydroxyvitamin D at concentrations found in normal human serum; this MAb has the potential to eliminate the lengthy extraction procedures involved in currently available assays for 1 alpha,25-dihydroxyvitamin D.
D000818:Animals; D000906:Antibodies; D000911:Antibodies, Monoclonal; D002117:Calcitriol / Q000032:analysis*; D003429:Cross Reactions; D051379:Mice; D008807:Mice, Inbred BALB C; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000032:analysis; D013950:Thymus Gland / Q000032:analysis
D000906:Antibodies; D000911:Antibodies, Monoclonal; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; D002117:Calcitriol