This method is usually used for mg/ml dosage of glucose. bellow 50 microg/ml I think the accuracy will be weak.

Are you measuring it in a culture media or in a physiologic fluid?

Sir, I m measuring it in culture media.

I used DNS for glucose determination in yeast culture- 10 years before- firstly, it is a primitive method since there is sulphuric acid addition around 10 ml- as far as I remember-. Since there is a need to work as duplicate, the job with the acid also duplicates also. DNS is for the glucose measurement for the culture media having glucose around g/L levels. But I changed DNS method with the glucose oxidase enzyme kit which is more sense, easy and practical eventhough thwe glucose level is enough high. In summary, there is no need to use DNS since it is " dirty" method and also since you can find more clean and practical methods to mesure glucose in the culture.