Identification of ALP-Linked Lmmmoglobulin by Immunoprecipitin Reaction in Free Liquid Media

Abstract

Enzyme-immunoelectrophoresis and enzyme-immmofixation on agar-agarose gel or cellogel membrane are usually used for the identification of alkaline phosphatase (ALP)-linked immunoglobulin (lg).However, there are some cases which could not be detected by these methods.
We applied the immunoprecipitin reaction in free liquid media for the sensitive method of the identification of ALP-linked lg. By this method, it is easy to determine existence of ALP-linked lg from ALP activity in immunoprecipitate formed by each monospecific antiserum. ln the presernt study, ALP-linked lgG (λ) was identlfied in all of 6 cas es by this method. The result corresponded with that from immunoelectrophoresis.Besides, we observed the change of ALP-linked lgG in clinical course and could confirm the sensitive method, by which ALP-lhked lgG in every case could be detected even that could not be detected by enzyme-immunoe-ectrophoresis.
High sensitivity of this method for the detection of ALP-linked lgG comes from that many precipitates were obtained and from that procedure time was short enough to avoid loss of ALP activity.
As ALP bound to lgG in almost cases, we also tested the method using Protein A-Sepha rose CL-4B.However its detective sensitivity was most, ALP-linked lgG3, lgA and lgM could not be identified.Therefore, the immunoprecipitin reaction was demonstrated as the simple, quick and reliable method to identify both class and type of ALP-lhked lg.