What could cause my ELISA runs to show gradient pattern in my OD readings across 12 replicates in a row?

My ELISA plate has 12 replicates of each sample in a row, and it shows an OD gradient. for example A1 (100mIU) if say has OD of 3.9 and gradient down to 2.9 OD at A12. I addressed different...

23 June 2022 9,433 1 View