Sentence:  In the present work whole sera have been fractionated by chromatography on DEAE-cellulose <WSD>using</WSD> single gradients similar to those described by Sober and Peterson , and certain chemical and serological properties of the fractions containing antibodies of the ABO and Rh systems have been described . 
Meaning of the word marked with <WSD> tags:  put into service; make work or employ for a particular purpose or for its inherent or natural purpose