Practical 6: Clinical Cytology

Question 1

What is a direct smear?
(3)

Answer 1

Quick and simple method to prepare slides for screening

Only used in diagnostic cytology

Cross method used to create a smear of cells for examination via speedy diff methods or for PAP staining

Question 2

How are your cultured cells prepared for a direct smear?
(3)

Answer 2

Specimens are centrifuged to concentrate cells in a pellet

The supernatant is decanted and the cell pellet is agitated to resuspend

A sample of this can then be used for your direct smears

Question 3

What is the main difference between air drying and dehydrating in alcohol for cytology?

Answer 3

Alcohol shrinks the cells -> loose cytoplasm to nuclear ratio

Air drying -> loss of some nuclear staining

Question 4

What is the cytospin method of preparing cells for cytology?

Answer 4

This is a method of creating a monolayer of cells in a small area for screening

Question 5

What is thin prep

Answer 5

Used mostly for cervical cytology but also for diagnostic cytology

Based on a filtration method

Cells are pre-treated with Cytolyt prior to transfer to PreservCyt vials for preservation

Sample is then processed on the ThinPrep 2000 or 5000 to achieve a monolayer of cells on a glass slide

Question 6

What are your staining results for the Speedy Diff stain?

Answer 6

Nuclei = deep purple/ blue
Cytoplasm = blue to mauve
RBC = salmon pink

Question 7

What are your staining results for the Papanicolau stain

Answer 7

Nuclei are blue/black
Cytoplasm is a spectrum of pink, orange, green (depending on maturation of cell)

Orange = glycogen stores are high = cell under pressure

Question 8

What is the principle behind the Papanicolau stain

Answer 8

It is a polychromatic stain that uses multiple dyes to differentially stain various components of the cells

Haematoxylin stains the nuclei

Orange Green 6: It is an acidic counterstain that stains the cytoplasm of mature keratinized cells. The components of the target stain orange in varying intensities of the dye

EA50 is a combination of dyes -> contains eosin, light green and bismark brown- this will stain the cytoplasm

Mature squamous cells = pink
Mature keratinised squamous cells = orange
Intermediate sequamous cells = green

Question 9

Compare your PAP and speedy Diff stains

Answer 9

PAP
- dehydrated/fixed cells
- shrunk cells
- can’t really see cytoplasm
- Well defined nuclear membrane and chromatin

Speedy Diff
- Air dried
- expansion of cells
- malignant cells expand more than normal cells