Your favorite assay for IL-6?

[Michiaki Masuda]

    I am attempting to measure the amount of IL-6 in the culture supernatant
of certain rat cells. There seem to be several assay methods for the
quantitative analysis of IL-6 including a bioassay using IL-6-dependent
cells and commercial ELISA kits. 

    I wonder if there is any good fool-proof method that could give me 
a result with a publishable reliability. I'd appreciate it if you folks
could let me know about your experience and give some advice.

    Thank you.

--Michiaki
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Michiaki Masuda
Visiting Associate
Laboratory of Molecular Oncology
National Cancer Institute
Frederick, MD 21702-1201
E-mail: Masuda at ncifcrf.gov