How to Choose an Enzyme Storage Lab Freezer

By Rachel Kohn | April 8, 2010

Enzymes are the catalysts of the biochemical reactions that comprise metabolism; they do their job without changing themselves in the process.    Enzymes are responsible for bringing about almost all of the chemical reactions in living organisms. Without enzymes, these reactions take place at a rate far too slow for the pace of metabolism.*

Enzymes being studied by researchers must be stored in a enzyme freezer at temperatures in the region of -10 to -25˚C (+14 to -13˚F).  When stored at higher temperatures enzymes gradually denature and lose catalytic activity.  Proper storage conditions are essential to ensure that the enzymatic activity on the label is indeed the activity inside the bottle.   I have many not so fond memories of failed experiments in graduate school because the rather costly purified enzyme suspensions failed to perform as expected, all due to inadequate storage.… Read the rest

A Primer on Drug Stability Testing in Stability Chambers

By Rachel Kohn | February 23, 2010

As described by the FDA, stability testing provides evidence of the effect of time and environmental factors on the quality of pharmaceuticals and medicinal products.  Such factors include light, humidity and temperature.  Stability tests also establish a re-test period for the drug substance or a shelf life for the medicinal product along with recommended storage conditions.

Stability tests are conducted in validated stability chambers such as manufactured by Norlake for pharmaceutical (ICH), biological (BOD), scientific and laboratory applications. These tests, which subject the product samples to variations in temperature and humidity, are conducted during drug product development as well as once a candidate drug reaches use and are governed by current good manufacturing practices (cGMPs). They are regulated in the U.S. by 21 CFR Part 211 Section 166. (www.gmp1st.com/drreg.htm#211.166)

While these tests are conducted in stability test chambers, it is not simply a matter of buying a chamber and plugging … Read the rest