Aikhan
I am happy to share my experience, and very inspirational your concern for the
burden on the patient and their families. Your language is just fine ! Do not
be concerned. We are on this list to help one another.
MW processing fairly common here. Some people love it, and some people are not
fully confident in it yet. My first advice would be that the biggest issue to
adoption seems to be understanding that it works differently than conventional
processing, though the end result accomplishes the same purpose. It works very
well if people take the time to learn to use it correctly. It is based more on
physics of MW energy and tissue components than just passive reagent diffusion
like conventional processors. It is wise to take some time to learn about how
this works before starting, though getting past this barrier should be easier
for you since you are not accustomed to using a conventional processor.
The vendors that I know are Thermo-Shandon, Sakura, Milestone -at least these
are the instruments I have personally used ( various models). They all have
advantages and disadvantages, it just depends on what your needs are. The
Milestone I would say is particularly adopted to very high volumes. The vendors
have proprietary technology and some reagents, but most use formalin, but just
accelerate the fixation rate with MW energy instead of convection heat and
agitation. The big concern is that you are working with much shorter times and
so you have to adjust your thinking on this aspect. Also some tissues- liver
cores, skins and bloody specimens such as endometrial biopsies will get very
dry if you are not careful with the heat and microwave exposure- my theory is
that is has to do with the polarity or water content of these tissues. The
outer surface becomes almost coagulated and tough, must like over-cooked food
in the microwave.
Important notes are:
That generally you cannot REPROCESS microwave processed tissue. So you have to
take the time to do it correctly from the beginning, and all tissue can be
sucessfully processed when a suitable program is set up. As you know, you CAN
reprocess with conventional, though the results are often not much improved. So
carefully consider this as you set up your process ( see below my suggestions
for this). The tissue thickness and overall dimensions are even more important
with MW than with any type of conventional processing to get uniform and
optimal results.
On the positive side, large samples( cut thinly), breast tissue and other fatty
specimens seem to do exceptionally well, much better than conventional. Graded
ethanols are typically used for dehydration as in conventional processing. So,
really most of the reagents are the same in the instruments I have used, with
the exception that isopropanol is substituted for xylene as a transition and
clearing reagent. Even though this seems counterintutitive, it actually seems
to work pretty well. If you are accustomed to processing manually, you will be
amazed at the tissue quality and speed you can gain by using any type of
automated processing- you will be leaps and bounds ahead if you are successful
in adopting microwave assisted processing.
Advantages
signifigantly reduce turn around, faster pateint results- some program are less
than 1 hour, really speeding up diagnosis. For some patients and samples this
may outweigh almost any disadvantagesthe vendors typically can assit with the
intial set up and this takes care of many of the issues I mention under
disadvantagescleaner, less exposure to hazardous chemicials
Disadvantages
Takes more time in the inital design of the programs,and validationYou may need
to customize or adjust programs for particular tissues more so than
conventional, so a little more technical attention and time is needed, in some
labs this may be a barrier
I hope that some of this information can be of help to you. Please let me know
if I can assist further in any way.
Joelle Weaver MAOM, HTL (ASCP) QIHC
Date: Mon, 17 Mar 2014 14:49:12 +0600
Subject: Re: [Histonet] Microwave Tissue Processing
From: aikhan...@gmail.com
To: joellewea...@hotmail.com
Hi Joelle Weaver,
From your posting I learned that you have experience of using Microwave tissue
processor for last 8-10 years. I would be grateful if you can help me in light
of your experience.
We are giving histopathology service in our country, Bangladesh.
We have a peculiar situation: Many patients are from rural areas, they come to
the city, have to stay till a diagnosis is made, an expensive matter for them
bearing all these costs; there's no insurance system here.
Presently tissue processing is manual in our lab; around 150 paraffin blocks
daily. Needing to produce rapid result under financial constraint we are
thinking of microwave processing, but we don't have any experience with these.
We know there are other choices as well: conventional carousel (like Shandon
