Paraffin is a mixture of hydrocarbons manufactured in the cracking of
mineral oil. A compatable paraffin of suitable hardness at room temperature
should be chosen for your specific environment. Paraffin's differ in melting
point according to their additives like diethylene glycol distearate,
ceresin, beeswax and even rubber. All these additives in combination react
differently when cooled to room temperature, sectioned, then placed onto the
water bath. The temperature of the water bath should always be approximately
10C below the melting point of the paraffin wax being sectioned.
Additionally, distilled xylene has an improved clearing capability before
and during infiltration of the paraffin. The major drawback of using
distilled xylene is during automated film coverslipping. Attention to your
dehydrant strength and its miscibility with your xylene may be an important
factor to consider.


Eric C. Kellar


 

-----Original Message-----
From: Sue Ryan
To: HistoNet@pathology.swmed.edu
Sent: 8/10/99 11:26 AM
Subject: Paraffin Problems

I hope someone can help us.

For the past month our paraffin surrounding the tissue has been blowing
up in the water bath.  We have two processors and the problem occured
in both machine.  The paraffin we used was Tissue Prep.  We also use
distill Xylene.  These are the steps we took.

1.  Switched to Surgipath infiltrating and embedding paraffin.  This
step didn't solve our problem.

2.  We put fresh Xylene into both stations for all processors.  We
still have the problem.

3.  We changed all solutions (formalin to paraffin) and the problem
still is happening.

If anyone has any suggestions please respond.

Susan Ryan HT, HTL
Path Lab Inc.
ryansue@yahoo.com
_____________________________________________________________
Do You Yahoo!?
Bid and sell for free at http://auctions.yahoo.com