There is a saying here in Texas, "if you don't like the weather just wait a few minutes and it will change", recently we had a great example. We experienced a thunder snow storm in the morning but then all melted off by time to drive home and the weekend temperature was in the 60's F. With such extremes in weather across the country, it is no wonder issues can arise with some of the products that we use in our labs.
Glacial acetic acid is one of those products, when the temperature starts going south, it may be delivered "as frozen as a popsicle" in an arctic blast. Needless to say a quick internet search tells us that Glacial Acetic Acid freezes at 62˚F (16.7˚C) so even here in the south, there is a chance you could see some of those ice like crystals, hence the name glacial. No worries, just let the product gradually come to room temperature. Caution- if applying heat, Glacial Acetic Acid is flammable and extremely corrosive so may be more prudent to be patient and be safe.
Hematoxylin crystals are another common occurrence that sometimes we come to expect and don't really realize that an excess of crystals may actually affect our staining results. The crystals are usually, the mordant that can come out of solution when the weather gets cold. If too much of the mordant(1)
comes out of solution and forms crystals in the bottle, your H&E stains may not be as crisp or as stable for as long as when it is warm outside. So don't be surprised if you have to change out your stains quicker than you are used to just to maintain consistent results. It is always a good idea to filter those brands of Hematoxylin that come with lots of crystals as you would hate a crystal to rear its ugly head on your stained slides.
And finally, some of you may have already experienced this but prefilled specimen containers can freeze in transit which is never a good thing for our patients. Since the freezing point of 10% Neutral Buffered Formalin is about 29˚F I would suggest trying to find a vendor that offers formalin prefills with a bit more alcohol, usually an extra 5% alcohol will do the trick. Of course don't forget that any changes in your fixatives may require a re-validation, costly yet potentially cheaper than having damaged tissue samples that may not be replaceable.
Wherever you happen to live, weather happens and life must go on so if you have questions or concerns, please let me know. Until next time...
(1)Aluminum Sulfate or Aluminum Ammonium Sulfate
- Debbie
