I have tried to weigh out lipolyzed collagenase to be used for stem cell culture, but it seems to either fall off- or blow off the sides of the spatula inside the fume hood where we measure out our chemicals. Does anyone have any techniques to reduce losing so much of the samples? I am using a very small and thin spatula, so that I am able to reach down inside the container and place 10 mg of collagenase into a 15 mL tube.
Hi Eden Klepper . Fluffy protein powder in small quantities can be very difficult to measure accurately. My solution was to make a stock solution, make single-use aliquots and freeze at -80oC. Collagenase is fine at -80oC for a long time.
I suggest using a suitable cardboard construction with a cover to surround the balance within the fume hood. It might be that you could find a commercial product, made of plastic, for this, as the problem is not unique. On the other hand, there may have been an MSDS (Material Safety Data Sheet) that shipped with the product (I hope that I am not old school, here). Read this to see if it suggests an appropriate level of precaution for using the chemical. Perhaps you may be able to get by, safely, with a lab coat, mask and gloves.
Don't wear gloves while weighing to reduce static in the system. Weigh into a boat an arbitrary amount and back-calculate the volume to get the concentration you want. Use a transfer pipette to dissolve the collagenase in the boat and then transfer to a tube.
We decided to make a solution, so that we lessen the chance of losing some of the collagenase powder each time. Thanks all for your help!
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