Counting cells

Question 1

Who created the haemocytometer?

Answer 1

Malassez

Question 2

What is a haemocytometer?

Answer 2

Specialised microscope made of thickened glass which is used to count cells

Question 3

What do the squares in a haemocytometer measure as?

Answer 3

0.2x0.2mm

Question 4

What is the depth of each square in a haemocytometer when a cover slip is placed over the platform?

Answer 4

0.1mm

Question 5

Stages of using a haemocytometer:

Answer 5

1. Shake sample to make sure it’s representative
2. Use an appropriate dilution so number of cells can be counted accurately.
3. Repeat process so that a mean can be calculated

Question 6

What is the North West rule?

Answer 6

Count dots on the middle of the triple line on the top or left side
Don’t count dots on the middle of the triple line on the bottom or right side

Question 7

Define flow cytometry

Answer 7

Electronic counting apparatus that uses a laser beam passed over a stream of blood to count cells

Question 8

What does a flow cytometer do?

Answer 8

Analyse characteristics of blood and counts particles, used in diagnosis of blood cancers

Question 9

Name the five parts of a flow cytometer

Answer 9

Laser, flow cell, 2 detectors (forward scatter and side scatter), fluorescent channels, computer

Question 10

Name the alternative to using a haemocytometer

Answer 10

Flow cytometer

Question 11

What are flurochromes used for in flow cytometry?

Answer 11

Tag different antibodies/bind to specific part of DNA, cell membranes or other cellular structures

Question 12

What does each flurochrome have?

Answer 12

Peak of excitation and emission wavelength

Question 13

Each structure fluoresces at different wavelengths so that they can be counted by a

Answer 13

detector.