Sentence:  The third , containing the mixed type of complete and incomplete antibodies , had titers of 1 : 256 in saline , 1 : 512 in <WSD>albumin</WSD> and 1 : 1024 by the indirect Coombs test . 
Meaning of the word marked with <WSD> tags:  a simple water-soluble protein found in many animal tissues and liquids