Soluble antibody affinity chromatography technique investigated with ultratrace [125I]thyroxine

An amount of 10 pg of [125I]thyroxine was subjected to DEAE agarose chromatography and then complexed with an antibody. Recycling of the [125I]thyroxine now as a complex with the antibody through a second DEAE agarose column under the same conditions gave a change in the retention of the [125I]thyroxine that potentially constitutes a specific shift away from co-eluting interferences from the first column. The [125I]thyroxine was then dissociated from the antibody and subjected to a third DEAE agarose column for additional shifting of its chromatographic retention. Since the overall recovery of the [125I]thyroxine is 36%, this soluble antibody affinity technique potentially is useful for sample clean-up in labeling analysis of ultratrace solutes such as thyroxine.