Home FAQs How stable is this enzyme? We dissolved our enzyme in water approx 2 weeks ago and the literature indicates that activity will start to drop after this length of storage time(and longer).

FAQ: How stable is this enzyme? We dissolved our enzyme in water approx 2 weeks ago and the literature indicates that activity will start to drop after this length of storage time(and longer).

Endoproteinase AspN stored at -20°C  that has been freeze-thawed more than a dozen times over a two week period should have good activity. The Endoproteinase AspN enzyme we sell is an apo-enzyme and lacks the zinc required for activity. We add zinc to our buffer to reactivate the enzyme (hence the good shelf life).