Diagnostic Role Of Blood Film

Question 1

What is a blood film?

Answer 1

A method of blood sample preparation which allows red blood cells, white blood cells and platelets to be spread evenly for microscopic inspection

Question 2

What is microscopy?

Answer 2

A technique used to examine samples (tissue, fluid, cells) that are too small for the human eye to see unaided

Question 3

Is all blood considered high risk?

Answer 3

yes, so a lab coat and gloves must always be worn

Question 4

What are the stains used?

Answer 4

Haematoxylin and eosin

Question 5

What does Haematoxylin bind to?

Answer 5

Acidic components of cells - particularly to DNA and therefore shows up in the nucleus

Question 6

What other stain works similarly to haematoxylin?

Answer 6

Leishman’s

Question 7

What is the colour of haemotoxylin?

Answer 7

purple-blue

Question 8

What does Eosin stain?

Answer 8

Binds proteins components, particularly in the cytoplasm

Question 9

What colour is eosin?

Answer 9

bright red synthetic dye, but stains pinkish

Question 10

What does Leishman’s Stain do?

Answer 10

Makes the nucleus visible

Question 11

Why are eosinophils called eosinophils?

Answer 11

They are cells with granules which were readily stained by the dye eosin

Question 12

What affects the performance of a light microscope?

Answer 12

The wavelength of light (you can’t alter this system)

The optical quality of lenses and all other components in the light path

The refractive index of the medium through which the light passes (which is why the highest resolution lenses are designed to use oil instead of air between the objective lens and the slide)

The physical properties of the objective lens

Question 13

What is the numerical aperture?

Answer 13

The numerical aperture of a microscope objective is the measure of its ability to gather light and to resolve fine specimen detail while working at a fixed object (or specimen) distance (not the same as resolution- but the higher the numerical aperture the higher the resolution)

It is written on the lens next to its magnification
(e.g., 10/0.25, means that the lens has a 10x magnification and a numerical aperture of 0.25)
It follows that higher magnification does not necessarily mean higher resolution

Question 14

What is the field Iris?

Answer 14

The light that comes from the bottom of the microscope

Question 15

What are the 2 types of light microscopes used?

Answer 15

Leitz microscope
Nikon microscope

Question 16

Are you comfortable naming parts of a microscope?

Answer 16

Question 17

What lens is it best to start with during microscope based practicals?

Answer 17

The Lowe power objective lens (4x)

Question 18

What is the correct order in which your should focus your image?

Answer 18

1. Focus the image
2. Focus the condenser
3. Adjust the field Iris
4. Adjust the condenser Iris

Question 19

How should blood be smeared onto the slide when preparing a blood film?

Answer 19

Place a drop of blood onto the glass slide and smear it away from you using a second piece of glass as a spreader - this ensures the blood drop stays behind the spreader otherwise blood cells might become damaged between the two slides

Question 20

What color does Leishmans stain turn nuclei?

Answer 20

Purple - blue

Question 21

What color does Leishmans stain turn cytoplasmic components?

Answer 21

Pink

Question 22

What color do white blood cells appear when being stained with Leishmans?

Answer 22

Blue

Question 23

What blood cell has a bi-lobed nucleus, with bright pink cytoplasmic granules when stained?

Answer 23

Eosinophil

Question 24

What blood cell has blue stained cytoplasmic granules and a lobed nuclei?

Answer 24

Basophil

Question 25

Which blood cells has a multi lobed nucleus with pink cytoplasmic granules?

Answer 25

Neutrophil

Question 26

Which blood cell has an indented nucleus and pale granules in its cytoplasm?

Answer 26

Monocytes

Question 27

What are elevated eosinophil levels indicative of?

Answer 27

Allergic reactions eg asthma or parasitic infections

Question 28

In what two circumstances might an increased number of basophils be found?

Answer 28

Chronic myelonous leukaemia hypersensitivity

Question 29

What is meant by the term left shift?

Answer 29

An increase in the proportion of band cel,s or the presence of neutrophil precursors in the blood

Question 30

The presence of what in neutrophils can be an indicator of bacterial infection?

Answer 30

Clear vacuoles

Question 31

What is seen in a blood film of a patient with CML?

Answer 31

A spectrum of granulocytes cells from myeloblasts to mature neutrophils

Question 32

What is the definition of megaloblastic anaemia?

Answer 32

anaemia in which maturation of the nucleus is retarded in relation to that of the cytoplasm.

Question 33

What are the most characteristic features of megaloblastic anaemia that are seen on a blood film?

Answer 33

Hypersegmented neutrophils and macrophages | Oval macrophages

Question 34

What is the function of the microscope stage?

Answer 34

To hold a microscope slide

Question 35

How is the degree of illumination of a microscope slide best adjusted?

Answer 35

By changing the lamp voltage

Question 36

What does a lymphocyte look like on a blood film?

Answer 36

Large round nucleus and relative lack of cytoplasm

Question 37

What is the key function of a neutrophil?

Answer 37

First line of defense in innate immunity and phagocytose microbes

Question 38

What are the key functions of monocytes?

Answer 38

Production of cytokines and phagocytosis of microbes and apoptose cells

Question 39

What are the key functions of lymphocytes?

Answer 39

Production of cytokines - T cells | Production of antibodies - B cells

Question 40

How are basophils activated?

Answer 40

Cross linking of IgE on their surface to release cytokines

Question 41

What are the main functions of eosinophils?

Answer 41

Defense against parasitic infections through the release of specific cytokines and also involved in inflammation as seen in asthma and allergy

Question 42

What are the non-nucleated blood cells?

Answer 42

RBCs and platelets

Question 43

What are RBCs role, their shape/ colour when stained and their size?

Answer 43

Most abundant blood cell, involved in O2 transport Biconcave shape, dusky pink 7 micrometers diameter

Question 44

What are platelets role, their shape/ colour when stained and their size?

Answer 44

These are important in blood clotting, and will probably be found in small clumps on a smear Bluish 2-4 micrometers diameter

Question 45

What are lymphocytes role, their shape/ colour when stained and their size?

Answer 45

Small cells with near spherical nucleus and little cytoplasm Involved in the immune response around 8 micrometres diameter

Question 46

What are Eosinophils role, their shape/ colour when stained and their size?

Answer 46

Bi-lobed nucleus. Implicated in fighting parasitic infections and allergy. Cytoplasmic granules are bright pink. around 12 micrometers diameter.

Question 47

What are neutrophils role, their shape/ colour when stained and their size?

Answer 47

multi-lobed nucleus (polymorphonuclear) cytoplasmic granules. Phagocytic cells which kill bacteria. 10-12 micrometers diameter

Question 48

What are monocytes role, their shape/ colour when stained and their size?

Answer 48

indented nucleus and pale granules in the cytoplasm. Phagocytic cells with a role in the immune response and inflammation. 17-20 micrometers diameter

Question 49

What are bosophils role, their shape/ colour when stained and their size?

Answer 49

cytoplasmic granules staining strongly blue lobed nucleus. involved in inflammation and allergic responses 10-15 micrometers diameter

Question 50

What are elevated numbers of eosinophils indicative of?

Answer 50

asthma and parasitic infection