1648
To study the complexity and structural characteristics of zinc finger proteins expressed during human hematopoiesis and to isolate novel regulators of blood cell development , a degenerate oligonucleotide probe specific for a consensus zinc finger peptide domain was used to isolate 63 cDNA clones for Kruppel-related zinc finger genes from the human monoblast cell line U-937 .
 ( cell line: human monoblast cell line U-937, None) , ( protein: zinc finger proteins, None) , ( DNA: Kruppel-related zinc finger genes, None) , ( DNA: cDNA clones, None) , ( protein: consensus zinc finger peptide domain, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( cell line: human monoblast cell line U-937, None) , ( protein: zinc finger proteins, None) , ( DNA: Kruppel-related zinc finger genes, None) , ( DNA: cDNA clones, None) , ( protein: consensus zinc finger peptide domain, None) 