Sentence:  In attempting to improve specificity of staining , the fluorescein labeled antisera used in both direct and indirect methods were treated in one of several ways : ( 1 ) They were passed through Dowex-2-chloride twice and treated with acetone insoluble powders ( Coons , 1958 ) prepared from mouse <WSD>liver</WSD> or from healthy sweet clover stems or crown gall tissue produced by Agrobacterium tumefaciens ( E. F. Smith + Townsend ) Conn , on sweet clover stems . 
Meaning of the word marked with <WSD> tags:  large and complicated reddish-brown glandular organ located in the upper right portion of the abdominal cavity; secretes bile and functions in metabolism of protein and carbohydrate and fat; synthesizes substances involved in the clotting of the blood; synthesizes vitamin A; detoxifies poisonous substances and breaks down worn-out erythrocytes