CPD ACCREDITED ARTICLE
remains, attempt a fine needle aspiration of the lesion,
and prepare as previously described. Cystic neoplasia
will not exfoliate overtly neoplastic cells into the fluid,
and the two types of material/methods might reveal
completely different cell populations.
CYTOLOGIST WISH LIST
Staining of cytological samples ✔ Don't place slide preparations in the fridge
It is generally not necessary to fix or stain slides
before submission to a laboratory as cytologists
prefer to fix and stain smears themselves, with stains
and techniques that they will adapt to the type and
thickness of the smear. Sometimes special stains are
required. All that is therefore required from private
practitioners is to air dry the smear, and to identify
and package them properly before submitting it to
a laboratory. Submit the sample together with the
patient history and identification and owner detail.
Smears must be stained within a week after making
them. Never submit slides for cytology in the same
package as samples in formalin. Formalin fumes diffuse
even from tightly closed containers and influence the
staining properties of the cytology slides. ✔ Don't place slide preparations anywhere
near formalin
✔ "Less is More" : excessive suction force
during aspiration causes more blood
contamination
✔ Use the correct collecion technique for
the tissue type (stab for fragile tissue and
aspirate for firm tissue)
✔ Don't get the feather edge right on the
end of slide - cannot focus properly
✔ Immediately place fluid samples into EDTA
✔ Take more than one sample to get a better
representation of the tissue
✔ Send in a few unstained direct smears with
fluid cytology
✔ In liver/spleen/lymphnode aspirates send
in a blood smear for comparison
If the slides are to be examined in-house, they should
be air-dried and can be stained with a modified
Romanowsky stain like Diff-Quik.
The following measures will ensure good staining
quality:
• Use only new clean slides. Samples will not spread
out well on re-used slides even if they are cleaned
and dried, as the surface properties of the glass will
have been changed.
• Use fresh, well filtered stains to avoid precipitates and
contamination with organisms or cell debris.
• Stain only completely air-dried slide, or dry slide
quickly with a hair dryer.
The most common problem encountered is under-
staining of slides. This will render cells and nuclei
pink (while nuclei should be dark purple, with a clear
demarcation of nucleus and cytoplasm). Neutrophils
on the slide can be used as an internal control for
staining quality. If understained, place the slide in the
stains for an additional time period. If immersion oil
has already been placed on the slide, wipe this off
gently and place the slide in the fixative solution for a
minute. This will remove the oil and also most of the
stain, and the slide will need to be restained.
Identify slides by marking with pencil on the frosted
end of the slide. Do not use paper labels to identify
the slide – the staining process will damage/dirty
paper labels or wash ink off.
Additional material from the internet
1. Refer to IVD 300 Clinical Pathology notes for information regarding sample dispatch to laboratory. This video will
remind you of the general principles: https://www.youtube.com/watch?v=JwcsQcQshBs&list=PLNjV05pK4JEVLl3x8_
mLYXxpjfMV-Gq4P&index=9
2. This video shows the stab (“woodpecker”) and aspiration (“syringe attached”) techniques for sample collection, as well
as how to make a squash preparation. https://www.youtube.com/watch?v=JTYJBNxeTH8
3. This video which shows how impression smears are made from biopsy samples: https://www.youtube.com/
watch?v=hey21Z459X0&t=2s
4. This video shows hoe smear from swabs are made. https://www.youtube.com/
h?v=GsLFO8zodKk&index=3&list=PLNjV05pK4JEVLl3x8_mLYXxpjfMV-Gq4P
Issue 01 | MARCH 2018 | 29