It is standard procedure in my lab that we do a calibration curve each time we do a colorimetric test such as measuring proteins or sugars in a sample.
On the other hand I learned in school that you only do your calibration curve once and you will verify with standards after that.
I have been searching on the internet but all I have been able to find is how to do one but not if I shouls do it every time (Which I personally think is not necessary)
Can anybody tell me if I should do one calibration curve every time I do a test and why?
Thanks very much,