1.2 horseblood Microscopy

Question 1

How to observe blood cells in a blood smear

Answer 1

1. gently shake sample to resuspend cells
2. Dip a glass rod into the blood and place a drop ¼ of the way along a microscope slide
3. Hold a second slide and angle about 45. push it back until it touches the drop of blood and then pull it forward towards the other side of the slide dragging a thin layer of blood behind it, leave to airdry
4. Calibrate the eyepiece Graticule with X40
5. pour ethanol on dry smear for 2 minutes
   This fixes and hydrates the cell
6. In the fume cupboard, put five drops of Leishman’s stain and leave for one minute
7. Add 5 drops of buffered water, leave for 5
8. wash the slide in Buffered water until it looks pale pink, blot dry with filter paper and cover with a cover slip at thinnest part
9. Examine the slide at X40
10. Dispose of blood-stained equipment in the disposal pot and wash your hands

Question 2

Why would we lower the cover slip at a 45 degree angle then press

Answer 2

Less air bubbles so cells are more visible

Question 3

Why do we use a sharp blade

Answer 3

So we can get a very thin piece

Question 4

Why do we select a thin piece

Answer 4

So we don’t get too many cells and light can go through

Question 5

What are the benefits of using stains when making slides

Answer 5

So you can see the difference between the white background and the cell
You can tell the difference from organelles and the nucleus if you use two different stains
You can tell the difference between different types of cells
Higher contrast from background
To produce clearer images