After chromogenic signal detection on a northern blot, circular colorless areas are observed on the membrane, obliterating bands and parts of bands. What is the cause of this?

Question

Quizplus · Accepted Answer

Circular colorless areas are likely to be caused by bubbles or incomplete contact between the membrane and the gel during the transfer step. This can prevent complete transfer of the nucleic acid and result in loss of signal from certain areas of the membrane. Incomplete electrophoresis (A) would result in partial separation of the nucleic acid and may cause smearing of the bands, but is unlikely to result in circular colorless areas. Loss of alkaline phosphatase activity (B) would affect the ability to detect the chromogenic signal altogether, and incorrect stringency conditions (C) may affect the specificity of probe binding but would not cause circular colorless areas on the membrane.

After Chromogenic Signal Detection on a Northern Blot, Circular Colorless