Figure 7. A melanopsin (OPN4)
peptide-blocking experiment was performed to test the specificity of
the antibody for western blot. Due to the presence of multiple bands on
the OPN4 western blot the OPN4 antibody was pre-incubated with a
fivefold excess of 15 amino acid N-terminal blocking peptide in 10%
milk/TBS-T for 2 h at room temperature before hybridization. Proteins
extracted from fenretinide (FR) and dimethyl sulfoxide (DMSO) treated
cells were incubated with OPN4 antibody pre-incubated with the blocking
peptide (OPN4+BP) or OPN4 antibody alone. A single band of
approximately 70 kDa specific to OPN4 was absent in the western
blot containing the blocking peptide.