Sentence:  Specific staining 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 <WSD>many</WSD> attempts with black and white and color photography . 
Meaning of the word marked with <WSD> tags:  a quantifier that can be used with count nouns and is often preceded by `as' or `too' or `so' or `that'; amounting to a large but indefinite number