Having gone through your publication on quantitative analysis of hCG, when there is much difference in the results from different systems - what is the best method to analyse it?
Article Are Laboratories Reporting Serum Quantitative hCG Results Correctly?
Are you trying to measure hCG or look for changes in responsiveness? When during pregnancy are you looking?
As noted in our publication, some procedures measure only intact hCG, while others, only the beta-portion. As for "best" it really depends on what you want to measure and why.
Robert Rej is correct there is no one best method for measuring hCG. Unlike steroids where one can obtain a pure crystalline standard to callibrate assays, glycoprotein are by nature a heterogeneous assamblage of different molecules and a large part of the answer to the question hinges on knowing if any or all of the various glyco forms are pertinant to the question you are trying to answer
I would second Dr. Blum that the immunoassay selection should be based on the purpose of the estimation. Pregnancy diagnosis from the urine sample is based on the beta subunit but monitoring the pregnancy for fetal well being and to rule out congenital abnormalities is done using intact hCG immunoassays. In tumors like testicular carcinoma / choriocarcinoma, although hCG is good enough but there could be some excess of beta subunit being secreted by the tumor cells - for this purpose the immunoassays that detect hCG + free beta subunits are most suitable.
WHO has defined certain reference standards for hCG kits. The 1st Reference Reagents for immunoassays with the following codes: hCG 99/688, hCGbeta 99/650, hCGalpha 99/720, hCGn 99/642, hCGbetan 99/692, and hCGbetacf 99/708. In contrast to the 3rd International Standard (75/537), the clinically most important Reference Reagent for hCG (99/688) contains no hCGn and negligible amounts of free subunits.
I know that Nigel Bennet uses a granulosa cell system to measure LH activity - progesterpone being the end product. Perhaps it will work for hCG
Thank you everybody for your comments. We are interested in knowing the activity of hCG rather its biological activity. Generally immunoassay gives you only immuno activity or immunigencity of the molecule, so how can we determine the biological activity of that molecule.
We work on the purification of the molecule, not interested in the pregnancy tests etc.
I agree with Henk in following the Nigel Bennett approach of using cell bioassay. We have recently used a tumour Leydig cell line (mLTC-1) with various LH peptides, including hCG, with good results.
Hey all i am looking for information on potters tower. Journal..manuals. Research papers, any info based on running bio assays in on the use of it in agriculture, for example mites. Thanks
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