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 chemical and serological properties of the fractions containing antibodies of the <WSD>ABO</WSD> and Rh systems have been described . 
Meaning of the word marked with <WSD> tags:  a dark-skinned member of a race of people living in Australia when Europeans arrived