Heterologous enzyme immunoassay for the determination of free indole-3-acetic acid (IAA) using antibodies against ring-linked IAA.
A solid phase indirect enzyme immunoassay method for the plant growth substance indole-3-acetic acid (IAA) using polyclonal antibodies raised to IAA linked to rabbit serum albumin (RSA) is described. The sensitivity for IAA increased by more than three orders of magnitude as the number of IAA ligands on the coating antigen decreased. Further improvements in assay sensitivity were limited by the high affinity of the antibodies for the bridge group in the IAA conjugate. Substitution of the IAA in the coating antigen by either indole-3-propionic acid or indole-3-lactic acid reduced antibody recognition of the bridge group. The resulting heterologous assay compares favourably with existing homologous immunoassays for IAA in terms of sensitivity and specificity.
Manning
K
K
Department of Plant Physiology, British Society for Horticultural Research, West Sussex, U.K.
D000818:Animals; D000906:Antibodies / Q000276:immunology; D003429:Cross Reactions; D006241:Haptens / Q000276:immunology; D007124:Immunoenzyme Techniques; D007210:Indoleacetic Acids / Q000032:analysis* / Q000276:immunology; D011817:Rabbits
D000906:Antibodies; D006241:Haptens; D007210:Indoleacetic Acids; C030737:indoleacetic acid