To see what was going on, he labelled the doxycycline-resistant strain with a yellow protein and the sensitive strain with a blue protein.

This article presents an indirect method of labelling proteins. an organic compound is labelled by radionuclide and then the compound is conjugated to a protein.

Effects of both groups were assayed with neurofilament nf protein and nerve growth factor receptor protein immunofluorescent double labelled staining laser confocal microscopy.