Sentence:  The only treatment by which nonspecific staining could be satisfactorily removed was by passing the conjugate through a DEAE-cellulose <WSD>column</WSD> . 
Meaning of the word marked with <WSD> tags:  a vertical glass tube used in column chromatography; a mixture is poured in the top and washed through a stationary substance where components of the mixture are adsorbed selectively to form colored bands