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 some cases to absorb the first and second milliliter fractions with <WSD>sweet</WSD> clover tissue powder . 
Meaning of the word marked with <WSD> tags:  erect annual or biennial plant grown extensively especially for hay and soil improvement