Lab Techniques

Question 1

What are Error Bars?

Answer 1

A from of statistical analysis. They are used to show the degree of variation within a group of numbers
If the error bars from 2 sets of data overlap, then it can be determined that the difference between the results is not significant (could be due to chance)

Question 2

Explain 2 Separation Techniques

Answer 2

• Centrifuge​ -used to separate substances of differing density. More dense components settle in the pellet; less dense components remain in the supernatant.
• Gel Electrophoresis​- used to separate proteins & nucleic acids. Separate proteins by their shape, size and charge

Question 3

Explain Cell Culture

Answer 3

• Animal cells are grown in medium containing growth factors from serum. Growth factors are proteins that promote cell growth and proliferation. Growth factors are essential for the culture of most animal cells.
• Plating out of a liquid microbial culture on solid media allows the number of colony forming units to be counted and the density of cells in the culture estimated. Serial dilution is often needed to achieve a suitable colony count

Question 4

what is Haemocytometer used for?

Answer 4

To estimate cell numbers in a liquid culture.

- Vital staining is required to identify and count viable cells (living cells)

Question 5

What is a serial Dilution?

Answer 5

In order to make a calculation of the numbers of bacteria in a sample, the original sample will need to be diluted - this is known as a serial dilution. Only when the sample is sufficiently dilute that it produces clear individual colonies can a calculation be made.