Unit 1.1.f

Question 1

What is the purpose of aseptic technique?

Answer 1

To eliminate unwanted microbial contaminants when culturing micro- organisms or cells

Question 2

How is aseptic technique carried out?

Answer 2

The sterilisation of equipment and culture media by heat or chemical means and subsequent exclusion of microbial contaminants.

Question 3

How can a microbial culture be started?

Answer 3

Using an inoculum of microbial cells on an agar medium, or in a broth with suitable nutrients

Many culture media exist that promote the growth of specific types of cells and microbes.

Question 4

How are animal cells grown?

Answer 4

In a medium containing growth factors from serum

Question 5

What are growth factors?

Answer 5

Growth factors are proteins that promote cell growth and proliferation.

Growth factors are essential for the culture of most animal cells.

Question 6

What is the difference between primary cell lines and tumour cells in culture?

Answer 6

Primary cel lines can divide a limited number of times

Question 7

What does plating out of a liquid microbial culture on solid media allow?

Answer 7

The number of colony- forming units to be counted and the density of cells in the culture estimated

Question 8

What is often needed to achieve a suitable colony count

Answer 8

Serial dilution

Question 9

What is the purpose of a haemocytometer?

Answer 9

To estimate cell numbers in a liquid culture

Question 10

Why is vital staining required?

Answer 10

To identify and count viable cells