17668
Samples of anti - crotalic IgY antibodies presented an efficiency of 246 mu l / 4 DL50 , a potency of 0 . 829 mg / ml and a specific activity of 0 . 271 .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None