Hello,

BSA is better than Tween 20 for blocking in ELISA.

Please refer to the research article given below.

https://doi.org/10.1006/abio.2000.4602

Best.

Hi Jalal,

In case it could be useful to you, we block with 1% BSA in phosphate-buffered saline (PBS) for 30 min/ 37 ºC,

and then, the sera diluted in 1% BSA, 0.05% Tween-20 in PBS.

Most people block with BSA (or at the very least a protein) but it is very common to add Tween 20 (0.1%) to the incubation and wash buffers for the purposes of reducing backgrounds.