Radioimmunoassayfor PantothenicAcid in Blood and Other Tissues

We describe a radioimmunoassay for pantothenic acid in biological tissues. c)-Pantothenic acid was conjugated with bovine serum albumin by use of a bromoacetyl derivative of pantothenic acid, and antibody to this antigen was raised by injectingitintothe fool pads of rabbits. For the radio-immunoassay, a 100-fold dilutionoftheresultingantiserum was incubated with radiolabeled pantothentic acid. The antibodies were precipitated and dissolved, and the ra-dioactivity of the solution was measured in a liquid scin-tillation counter. Between 5 and 125 ng of pantothenic acid can be detected in 75 zL of tissue extract. Validation in-cluded recovery and precision studies, parallelism with tissue extracts, and competitive binding studies. Results of the radioimmunoassay and those of microbiological assay with use of Lactobadilus plantarum correlated wel