The enzymes within the K-TDFR kit are quality control tested prior to packing.
The activities of these enzymes are tested and once these enzymes are stored correctly then they will not drop in activity. Our enzymes are stable for a number of years when stored correctly.
If the kit is used within the 6 month time frame then there would be no need to test the enzyme purity. However, it would be recommended to test purity of the enzymes if you were to return to analysis after 6 months.