Preparation of 125I-protein A usable for up to 10 months in immunoassays
1984
Abstract Chloramine-T iodination of protein A from Staphylococcus aureus and gel electrophoretic purification of the iodination mixture results in a stable tracer of high specific and functional activity. Following repeated gel electrophoresis of the tracer only a single component was observed. The specific activity of the 125 I-protein A was between 30 and 55 μCi/gmg. The binding of 125 I-protein A to rabbit immunoglobulin exceeded 90% and the tracer competed effectively with unlabeled protein A in binding to cells incubated with sera containing surface antibodies. Storage of the tracer for up to 46 weeks resulted in a moderate decrease in maximal binding to immunoglobulin (from 91% to 64%), in TCA precipitable radioactivity (from 97% to 80%) and an approx. 30% decrease in the ability to detect cell bound immunoglobulin. It is concluded that gel electrophoretic purification of 125 I-protein A produces a tracer with a very long shelf life.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
14
References
7
Citations
NaN
KQI