cassettes with or without lids, paraffins

From:Gayle Callis

Isabelle and others,  

No error would occur if one works with one cassette at a time ie opening
one cassette then embedding that tissue BEFORE opening up another cassette.
This was mandated in a clinical lab worked in many moons ago, we even wiped
forceps between samples! Have worked with both designs, opt for attached
then disposable lids, dislike cleaning metal lids intensely. 

Inherent dangers lurk in cassettes with faulty designs, hinge openings that
could allow a tiny tissue to slip out or poor lid design where it releases
or fasten down securely so that during processing, pop open resulting in
tissue loss or mixup in processor, heaven forbid! 

As for pricing, there may be some expense differences. Most cassettes are
reliable and good deals lurk if one shops around, ask for discounts and
samples too see what you are getting. 

Paraffins vary, the additives are proprietary and contribute to melting
point, sectioning quality, infiltration, etc. Each manufacturer will have a
slightly different product. Some people swear by their favorite paraffin as
being the only one to use- I'm no different with likes or intense dislikes,
but most paraffins work well. Vendors will send samples if you ask. 

Remember that good sectioning will start with total fixation followed by
good tissue processing, decent microtome in good working order, and good

I suggest you also purchase a general all purpose histotechnology textbook
to help you out, a wealth of info at your fingertips, not saying you should
not ask questions on Histonet.  Go to Histonet Archives, a list of books
has been given in the past.  

Good luck on setting up you lab.


Gayle Callis
Histopathology Supervisor
Veterinary Molecular Biology - Marsh Lab
Montana State University - Bozeman
19th and Lincoln St
Bozeman MT 59717-3610

406 994-6367
406 994-4303 (FAX)

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