Real lab failures, root causes, and fixes — curated and bilingually annotated by our team.
Western blot film shows very faint bands or no visible bands after initial exposure. The membrane may contain protein and antibody binding has occurred, but the chemiluminescent or colorimetric signal is not captured adequately on film.
Western blot shows weak or barely detectable bands even with adequate exposure time. Positive controls may show reduced signal intensity compared to expected results, indicating suboptimal antibody binding.
Western blot yields weak signal despite using appropriate antibody concentrations and sample amounts. The antibody-antigen binding has not reached equilibrium, resulting in suboptimal signal development.
Western blot shows no signal or extremely weak signal when using HRP-conjugated secondary antibodies. Chemiluminescent substrate fails to produce expected light emission even with adequate antibody binding and exposure time.
Western blot using alkaline phosphatase (AP)-conjugated antibodies shows weak or no colorimetric signal development. The BCIP/NBT or other AP substrates fail to produce expected colored precipitate even with adequate incubation time.
Western blot shows weak or no signal for target protein. Loading controls may also appear faint, indicating insufficient total protein loaded per lane. This is particularly problematic for low-abundance target proteins.
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