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 sweet clover <WSD>tissue</WSD> powder . 
Meaning of the word marked with <WSD> tags:  part of an organism consisting of an aggregate of cells having a similar structure and function