What are the acceptance criteria when testing the kit control in the K-TSTA kit?

For starch assays such as this a deviation of +/- 5% is generally accepted within our laboratory. We regularly run this assay in our laboratory and obtain results within +/- 2%. 

However, each laboratory is different and it is up to each individual laboratory to determine their acceptable limits as the analyst and experience levels with this assay can play a factor.