Sentence:  Specific <WSD>staining</WSD> by DEAE-cellulose treated * * f and * * f , although clearly distinguishable under the microscope from either nonspecific staining or autofluorescence of cells , was not satisfactorily photographed to show such differences in spite of many attempts with black and white and color photography . 
Meaning of the word marked with <WSD> tags:  (histology) the use of a dye to color specimens for microscopic study