Sentence:  In our work the best procedure for removing substances causing nonspecific staining in order to obtain specific conjugates was to pass the conjugates through a DEAE-cellulose column and in <WSD>some</WSD> cases to absorb the first and second milliliter fractions with sweet clover tissue powder . 
Meaning of the word marked with <WSD> tags:  quantifier; used with either mass nouns or plural count nouns to indicate an unspecified number or quantity