How to normalize ELISA measurements? - Total protein, cell number, or DNA? (Nov/13/2008 )

Hi All,

I am measuring the level of OPG in my conditioned media using ELISA. Which of the following is the more accepted way of normalizing the OPG measurements?

1. total protein content (using BCA or Bradford)
2. total cell number (simply trypsinizing and counting the number of cells)
3. total DNA

Thanks!

We used total protein content for ELISA normalization.