Hi people, this is my last post for SIP. Hope you guys are doing fine for your project. :) I have been posted to the trimming room for this month and will be talking about processing for this post.
In the trimming room, pathologists will trimmed large biopsy specimens or specimens that are too big for the technicians to pass. Some of the large specimens are breast, colon, uterus etc. Basically, my job is to assist the pathologists. In the morning before they arrive, my job is to distribute the specimens and write cassettes. Normally for the large specimens around 10-12 cassettes are needed while for those very small 1-2 is enough.
Specimen example colon is labeled with eg.A, B or C etc, according to the alphabet that is written on the form. In other words, if the pathologists uses 14 cassettes for the colon specimen, the cassettes will be written until eg. A14. During the labelling of the cassettes, one have to remain alert and make sure that the correct biopsy number is written, otherwise wrong diagnosis will be given. Following that, i need to make sure that there are enough trimming blades and scalpel, paper towels and paint, so that they do not run out during trimming.
After the trimming is completed for the specimens, the cassettes have to be put into a rack which is soak in 10% neutral buffered formalin. The purpose of this is to fix the specimen. After that, the cassette rack will be placed into the automated tissue processor for processing. There are basically three main steps for processing, which are dehydration, clearing followed last by infiltration.
Dehydration
Principle: It is to remove the water contain inside the tissues so that wax can infiltrate as wax is not miscible with water. (Ethanol is used in this case)
Clearing
Principle: It is to remove the alcohol from the previous step using an agent that is misicble with both the wax and alcohol and for clearing purpose. (Xylene is used)
Infiltration
Principle: It is to replace the clearing agent with embedding medium (Paraffin wax is used)
Zi Shuang
0703383J
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Hi Zishuang,
ReplyDeleteIs there other alternative reagents that can be used for the various steps of processing?
Lok Pui
Hi Zishuang,
ReplyDeleteAs you say there are different large specimens, so do you use different reagents for different specimen or its the same for all specimens?
thks!!
Zhang'e
0704086H
TG02
Hi Zishuang,
ReplyDeleteYou mentioned that you need to ensure that there is enough paint. What is paint used for?
Yvonee
0703189A
Hi Zishuang,
ReplyDeleteThanks for the post. Something to clarify.
Trimming is to cut larger pieces of tissue into smaller pieces ? A14 means the 14th part of tissue A being cut into 14 (or more) pieces ?
Thanks
Ng Tze Yang Justin
0703747F
hi lok pui, here are some alternative reagents that can be used:
ReplyDeletedehydration: methanol, acetone, isopropanol
clearing: toluene, chloroform
for infiltration, paraffin wax is more common as it is cheap, easily handled and allow sectioning with few problems.
Thanks for the question :)
Hi zhang' e, regardless of which specimen be it big or small we use the same reagents as it would be too troublesome to customise wad reagents we use for which specimen :)
ReplyDeleteThanks for the question
To Yvonne:
the paint is bascially what pathologists use to paint the different parts of the tissue specimen, it is sort of like an indication, for example posterior margin paint red, inferior margin paint blue , superior margin paint yellow etc.
To Justin:
A-14 generally means that there are 14 pieces of trimmed tissues from the specimen and if the pathologists request for more cassettes we have to label them
Read on cryptococcus latex test principle and procedure
ReplyDeletehttps://mltgeeks.com/latex-cryptococcus-antigen-test-crag-principle-and-result-interpretation/