Hello. I am here looking for help with the NO radical scavenging assay. I was working on setting up the assay with sodium nitroprusside and the Griess reagent as they do in most works. However, I do not find the conditions for the calibration curves (with ascorbic acid, Trolox or Gallic acid) to be linearly related to the measured absorbance. The curves I built with these patterns are all asymptotes. I haven't found much detail about curves in the works I read. I appreciate any help!