for the past 3 weeks, i have been posted to the cytology lab. the atmosphere in the cytology lab is definitely much cosier, probably because the specimens received in the cyto lab is much lesser as compared to the amount of specimens received in the histo lab.
In cyto lab, specimens are categorized into two fields; gynaecological specimens and non-gynaecological specimens. gynaecological specimens are cervico-vaginal smears while non-gynaecological specimens are sputum, urine, CSF and other fluids(peritoneal fluids etc).
1. The gynaecological specimens are received along with the requisition forms.
a) Ensure that the identification number on the slides tally with the number of the forms.
2. The specimens are then fixed in 95% alcohol.
3. The specimens are then loaded into a rack to be placed in the pap stain machine.
Principles of pap stain.
The papanicolaou stain method is a polychrome staining reaction. It is used to portray the variations of cellular maturity and metabolic activities. This method can be used for cervico-vaginal smears and smears from the different bodily secretions which includes respiratory and digestive, to detect the presence of cancer cells. The pap stain involves 3 different types of stains; the Harris haematoxylin, Orange G and EA50. The harris haematoxylin will stain the nuclei blue. EA 50 is made of three elements. The different elements are eosin, Bismarck brown and fast green. The combination of Orange G and EA50 is responsible for the different range of green, blue and pink hues to the cell cytoplasm according to the degree of keratinization of the cell. The cytoplasm of non-keratinized, normal superficial and intermediate squamous cells are stained green. However when the cells are keratinized, the staining becomes orange and pink.
Note: The slide with the specimens smeared in a thin, monolayer manner will give the best staining results. This is because the thickness of the section will affect the intensity of the staining.
4. The stained slides are then placed in a container filled with xylene.
5. The slides are mounted manually.
a) Just enough depex is filled on a cover slip.
b) Take a slide from the rack in the xylene and place it on the cover slip.
c) Ensure that there are no bubbles present between the slide and slip.
d) If bubbles are seen, press the slip gently to allow the bubbles to escape.
e) If there are too many bubbles seen, the slide should be remounted.
f) To remount the slide: Place slide in a container with xylene until the cover slip dissociates
and until the mounting medium is removed. Then, mount as usual.
6. The mounted slides are left to dry.
7. Label the slides according to the lab number.
8. The slides are ready to be screened.
Nurathirah
0606561I
Tg 01
10 comments:
Hey.. Why are the stained slides placed in xylene? What is the purpose of xylene? Thank you!
Siti Nurfatin
0605853A
TG01
hi athirah,
i'd like to know if the smears are done in the same way as how we smear the normal PBF? or is it smeared in a special way? and what is depex? thanks.
Malerie
TG02
Hi!
you mention at the last step, sceening the slides you've stained. do you read them under mircocope manually or by automated machines? and i wonder what you can see from the sildes. =)
thanks,
Yumei
Hey :)
As you have said that gynaecological specimens will arrive as glass slides yes? how about non-gynaecological specimens? And, can u show us some pictures of cancer cells stained by the pap stain?
Thanks!
Yvonne Teo
Hi. =)
I'm curious if the lab you are in is automated since you mentioned that you load the specimens into a rack to be placed in the pap stain machine.
Erm .. Can you explain briefly how cell cytoplasm can be keratinized? Like what causes them to become keratinized.
And also, what's a depex and what it is used for?
Thanks. =)
Lyn
0611027D
TG02
athirah!ATHIRAH!
i'dike to know the range of thickness of the tissues on the slides, as you said that the thickness affects the staining.
thank you
Rusydiana
0608485i
Hi Athirah!
I would just like to know 1 thing:
1) why would the thickness of the specimen affect the intensity of the staining?
Hope it is not too much trouble for you.
Many thanks
Quan Jun
TG02
Group 08
Hello Nurathirah,
Ive got 1 question for you
1) What is the principle of fixing specimen with 95% ethanol and not other concentrations?
Thanks!
From: Benjamina Ma
Class: TG01
0606181F
siti nurfatin-
xylene acts as the clearing agent. it is also miscible with the mounting medium. hence, its usage :)
malerie-
there are actually a few methods to make a smear. one of the most common method in the lab is the "touch and pull". it is when you use put two slides together and you pull them in the opposite direction to spread the smear. depex is commonly known as DPX. It is a mounting medium.
yumei-
oh we screen the slides under the microscope to check the staining. whether the nucleus is overstained or the cytoplasm is poorly stained or vice versa.
yvonne-
as i have mentioned in my entry, non gynae specimens are fluids. like csf, peritoneal fluid, knee aspiration. when we process them to make smears, that's when we put them on slides. i will try to get the picture up soon.
lyn-
it's not completely automated. yes, the staining is. however, the processing is done manually excluding the centrifugation part. even the mounting is done by the med techs. depex is actually DPX. sounds familiar now? DPX is the mounting medium.
rusy-
there is no exact range of the perfect thickness of smear but, the cyto tech told me that just one drop of the fluid is enough.
quan jun-
if the smear is too thick, under microscopy, you will see cells overlapping each other. hence, that could cause misdiagnosis because perhaps the cancer cells have been overlapped, causing a false negative result.
benjamin-
i think at 95% concentration, it provides the optimum fixing results.
thanks for the questions guys!
Athirah, you did not answer benjamin's question correctly. What is the principle of fixing the cells at 95% ethanol? How does the cells get fixed? Why other concentration cannot fixed the cells?
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