Marie-Therès: It's better to use some kind of reference to express your cAMP level in ELISA assay.  Protein concentration is one of them.  You can also use total ATP if its not too difficult to quantitate.

Hi Marie, 

It's better to normalize the cAMP concentration to the total protein concentration for each sample and this will make it easy to express the data as picomoles of cAMP per mg pf total protein. Hope this answers your question. good luck!

Dear Marie-Therès Wanuske

Pls. find the attached files, most of protocol not clearly mentioned to adjust of protein concentration before performing a cAMP elisa, for of that you may start it

https://www.ncbi.nlm.nih.gov/pubmed/11882904

https://www.ncbi.nlm.nih.gov/pubmed/11444827

http://www.enzolifesciences.com/ADI-900-163/camp-complete-elisa-kit/

http://www.biovision.com/manuals/K371.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3164349/

http://www.sigmaaldrich.com/catalog/product/sigma/ca200?lang=en®ion=SY

http://www.blossombio.com/pdf/products/UG_ADI-900-066.pdf

http://www.biocompare.com/pfu/110627/soids/2078/ELISA_Kit/cAMP

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050918

http://www.biotek.com/resources/articles/live-cell-assay-interrogate-gpcrs.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2118605/

http://www.merckmillipore.com/INTL/en/product/cAMP-Direct-Immunoassay-Kit%2C-Colorimetric,EMD_BIO-116811?ReferrerURL=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26rct%3Dj%26q%3D%26esrc%3Ds%26source%3Dweb%26cd%3D6%26cad%3Drja%26uact%3D8%26ved%3D0ahUKEwih0Ymrr_vPAhViOMAKHet7D6QQFghEMAU%26url%3Dhttp%253A%252F%252Fwww.emdmillipore.com%252FCA%252Fen%252Fproduct%252FcAMP-Direct-Immunoassay-Kit%252C-Colorimetric%252CEMD_BIO-116811%26usg%3DAFQjCNEp8OzFQ_Py_ytntqT4vOSo_oknLw%26bvm%3Dbv.136811127%2Cd.d24&bd=1

https://www.researchgate.net/post/Does_anyone_have_a_detailed_protocol_for_measuring_cyclic_AMP_in_mouse_islets

http://www.enzolifesciences.com/ADI-900-066/direct-camp-elisa-kit/

http://www.abcam.com/camp-direct-immunoassay-kit-ab65355.html

Regards

Prof. Houda Kawas

Thank you all for your replies. I know that there is unfortunately no mentioning of protein-amount adaption in literature or manufacturers-protocols. I will try to perform a BCA protein quantification with the HCL lysates and adjust it in the ELISA.