Sentence:  Treatment of the conjugates with ethyl acetate , and the conjugates ( which had been passed through Dowex-2-chloride ) with mouse liver powder , sweet clover crown gall tissue powder , or healthy <WSD>sweet</WSD> clover proteins did not satisfactorily remove nonspecifically staining substances in the conjugates . 
Meaning of the word marked with <WSD> tags:  erect annual or biennial plant grown extensively especially for hay and soil improvement