title: Determination of total choline in biological materials.
abstract: A microbiological eight-point parallel line assay for the determination of choline has been developed, using Neurospora crassa cholineless-1 as test organism. In the common procedure the mold is grown at 25 degrees C in 25 ml basal medium at pH 5.9-6.0. Growth studies showed, however, that a better log dose-response curve, with respect to the linear part of the curve, was obtained when the organism was grown at 30 degrees C, in 20 ml experimental volume and at pH 5.5. The proprosed eight-point assay was tested by comparison with the common procedure. Although repeated analyses of a test solution showed no significant difference in the mean values obtained, a greater scatter of the single values about the mean was observed when analyzing according to the common procedure. The developed procedure was also applied to different samples of biological material. The analysis of variance proved the parallelity and linearity of the dose-response curves. As a result of the variation between the replicates could be used as the experimental error of the assay when the confidence limits of the samples were computed.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002794:Choline / Q000032:analysis*; D005399:Fishes; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000378:metabolism*
chemical_list: D002794:Choline