7969
3600 - fold to apparent homogeneity with a 41 % yield by affinity chromatography utilizing DNA - cellulose ; the purity of the final preparation was assessed by SDS / PAGE , lack of contamination by other nucleases and production of a monospecific antibody against the enzyme .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 None