I carried out TFC determination using NaNO2-AlCl3-NaOH assay in 96 well plates. However, after repeating a few times using the same methods and volume the result is inconsistent. I realised the complexity formed is not homogeneous that contributed to the inconsistent results. I did try a few ways such as increase the replicates, shaking and stirring after complex formed and lengthen the time until stable complex formed. These ways did not help much. Should I try different method instead? Anyone has faced the same difficulty before and how did you overcome it? Would really be great if someone could suggest other ways to tackle such problem. Thank you