6068
B cells were purified from buffy coat preparations of healthy blood donors by positive selection using an anti CD20 monoclonal antibody and a MiniMACS separation unit .
 cell type: B cells; protein: CD20; protein: anti CD20 monoclonal antibody
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: B cells, CD20, anti CD20 monoclonal antibody 
Answer:
 cell type: B cells; protein: CD20; protein: anti CD20 monoclonal antibody