Microscopy of blood cells Flashcards
What does the objective lens do
brings objectives of different magnifications into the light path.
What does the condenser iris do
adjusts opening of condenser iris diaphragm
What does the field iris do
adjusts opening and closing of the field iris diaphragm
What does the centring screw do
adjusts the position of the condenser iris.
What does the lamp voltage control do
adjusts the brightness of the image
What does the condenser focus knob do
brings condenser iris into focus.
In practice, how do you achieve optimal resolution
Set up the condenser correctly,
What happens at x40
As you change the condenser, structures overlap, resolution is spoiled, closing condenser iris too far also spoils resolution.
Why do we use stains
Few cellular components absorb light at visible wavelength, hence in order to see cells and their organelles, we stain them with special dyes.
What is Haemotoxylin
purple-blue component- binds to acidic component of cells- binds to DNA
What is Eosin
pinkish stain that binds to protein components in the cytoplasm.
What is the alternative to using stains
To exploit the interference properties of light to detect the different refractive indices of cells compared to the surrounding fluid (ECM)- this requires a microscope fitted with special optics and is especially important when examining living cells.
What is Leishman’s stain
Contains a purple-blue dye- stains nuclei. Pink dye stains components in the cytoplasm.
How does a red cell appear under the microscope
Dusky pink
How do platelets appear under the microscope
Small clumps
