Sentence:  The <WSD>red</WSD> cells for the Rh antibody tests were used within 3 days after drawing except for the * * f cells , which had been glycerolized and stored at - 20 ` C for approximately 1 year . 
Meaning of the word marked with <WSD> tags:  a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus