Table 1 below shows the samples you will prepare for the ONP
     Table 1 below shows the samples you will prepare for the ONP standard curve.  Identify which sample(s) represent(s) the negative control. Tube #  Identify which sample(s) represent(s) the positive control. Tube #  Explain your answers for Question 9 above. 
  
  Solution
ONP is the product formed when enzyme acts on ONPG. Tube 1 is negative control. Hence, in tube 1 since there will be no ONP, hence it will help us to know the response when there will be no formation of ONP which is negative control. While tube 7 ONP is in maximum volume, that will help to understand when there will be the positive response. Hence, it is positive control.

