Sentence:  In the present work whole sera have been fractionated by chromatography on DEAE-cellulose using single gradients similar to those described by Sober and Peterson , and certain <WSD>chemical</WSD> 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:  material produced by or used in a reaction involving changes in atoms or molecules