Sentence:  In the present <WSD>work</WSD> whole sera have been fractionated by chromatography on DEAE-cellulose using 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:  a product produced or accomplished through the effort or activity or agency of a person or thing