Black edges on a membrane when visualizing a Western blot can be due to several causes. Here are some avenues to explore to troubleshoot this issue:

Membrane saturation : If the membrane has been exposed to the detection solution for too long, it can cause saturation of the edges and buildup of reaction product, creating black edges. It is important to control the incubation time with the reagents.

Reagent concentration too high : Too high a concentration of antibodies or detection solution can also cause excessive background and artifacts around the edges. Be sure to use the correct recommended concentrations for each reagent.

Wash buffer issue : If the wash buffer is improperly prepared or too concentrated, it can cause reagents to build up at the edges of the membrane, creating black artifacts. Make sure the buffers are prepared correctly and that the wash is performed uniformly.

Transfer issue : If the protein transfer to the membrane is not uniform, it can cause visible artifacts after development, especially around the edges of the membrane.

Membrane contamination : The presence of contaminants on the membrane before or during transfer (such as fingers, pipette marks or chemicals) can also cause visible artifacts at the edges. (which does not seem to be your observation here)

To correct this, you can try to optimize the following steps : check the reagent incubation conditions, adjust the reagent concentrations, check the quality of the wash buffer and examine the quality of the transfer.

Hi, in our lab, we recently have the same problem with WB, we have changed all reagents, we made sure of everything that was suggested in the previous answer, however we still have the same problem. Have you been able to solve this issue? Any suggestions to solve it? Thank you very much.