Three fine products make up the family of Paraplast® Tissue Embedding Media. All are highly purified paraffins of specific molecular weights and are formulated with varying amounts of special polymers to produce special characteristics. All three formulations section easily but also, do exhibit differing characteristics which might be important for specific tasks. We give guidance on the selection of the right grade but ultimately, most users starting out, seem to have the need to try two or possibly all three formulations and then make some determination as to which is best for them.
Shelf life issues:
Paraplast is a very stable system, both in the bag was well as in the form of an embedded block. The guarantee for Paraplast is for five years, assuming that the product is stored at the recommended storage conditions. Of course, exposure to heat will eventually melt the wax pellets together, but even the fused product is still going to be "good". Exposure to prolonged heat can evaporate off some of the more volatile components of the composition, and in that case, one could expect changes in performance.
There is no particular warranty for Paraplast in the form of a cured block but some histologists report storing blocks for as long as thirty years and find them still well preserved and available, if needed for further study. Accidentally get some hot Paraplast on your good clothes? A hot iron with a paper towel underneath should solve most if not all of the problem. We cannot guarantee this "solution" will work in all instances but it does seem to work in some cases.
Just getting started?
We are often times asked to "recommend" which grade to use and more often than not, our ability to predict is no better than that of our customers. But we find that over all, about 50% of the sales are of the "original" Paraplast, with 25% being for Paraplast Plus and the remaining 25% being for Paraplast&