Hi,

I'm analyzing cortisol in post smolt salmon with two elisa kits. The first is made for human saliva (Fairly cheap) and the second one for fish (three times the price). I was hoping to get significant data using the saliva kit but unfortunately the values I got using this kit were way bigger than those with the fish kit. The plasma samples I used were quiet old, but stored appropriately. I would like to know whether the difference is linked to cross reactivity, and which compound may be responsible.

Many thanks!