The way I read it, the kits just use different orders of magnitude to ascribe a rvd1 concentration, in which case the numbers should simply be 1000x higher in case of pg/ml. Does the concentration of the ELISA kit refer to the concentration in the sample, or to the concentration in the diluted sample you add to the plate?

Hi dear Wesley,

Thanks a lot for your comment.

No, RvD1 ELISA kit did not refer to the concentration of RvD1 in the sample or to the concentration in the diluted sample.

http://www.fatsoflife.com/pufa-august-2014/reference-profiles-pufa-derived-lipid-mediators-human-plasma-serum/

Hi Ramin,

The difference in sensitivity you mention looks quite huge to me. However, I believe that the differences in sensitivity as well as in absolute values themselves are at least partially due to the nature of the antibodies used in these kits as they may be directed against different antigenic targets. For instance you can also get substantially different values when you compare cytokines or growth factors data by a given ELISA assay and Luminex. If you want to compare your data to those in literature, I would recommend that you select one ELISA kit that is frequently used by other authors (or that you validate the kit you wish to use -e.g. due to lower cost- against the standard kit). Kind regards, Thierry

Hi dear Thierry,

Thank you for your comments.

Thanks a lot for your kindness.

Best regards,

Ramin

Unfortunately, the problem highlighted by Ramin causes problems of sensitivity, specificity and comparability for most immunoassays. I agree completely with the Thierry analysis which attributes the most responsability to the binding characteristics of different couples antigens/antibody. The various signal detection modes must be even considered