THE INFLUENCE STRUCTURE OF LABELED ANTIGE N ON SENSITIVITY AND SPECIFICITY OF POLARIZATION FLUOROIMMUNOASSAY OF 2,4-DICHLOROPHENOXYACETIC ACID (2,4-D)

Effect of the length of linker ((CH2)n, n = 2, 4 or 6) between antigen and fluorescent label on specificity of antibody to 2,4-D and detecti on limit of 2,4-D by the polarisation fluoroimmunoassay was studied. M aximum antibody binding was observed in case of the labelled antigen w ith the longest linker (n = 6), slowly decreasing as the linker shorte ned, whereas specificity of antibody, upon linker's shortening, increa sed (detection limit was 4,8 mug/ml at n = 6 but 0,5 mug/ml at n = 2). The shortest linker (n = 2) is to be used for working out high specif icity PFIA to 2,4-D, the longer linkers (n = 4, 6) being preferable fo r the aryloxyalkylcarboxylic acids assay.