Lab technique

Question 1

Colorimeter

Answer 1

To quantify concentration and turbidity

Question 2

Blank

Answer 2

Deionised water

Question 3

Centrifugation

Answer 3

Separates substances according to differing density

Question 4

Pellet

Answer 4

The more dense components

Question 5

Supernatant

Answer 5

The less dense liquid fraction

Question 6

Paper and Thin Layer chromatography

Answer 6

Separates substances such as amino acids and sugars according to solubility

Question 7

Affinity chromatography

Answer 7

Separates a specific soluble protein

Question 8

Gel electrophoresis

Answer 8

Separates proteins or nucleic acids using current flowing through a buffer. The proteins are separated based on shape, size and charge.

Question 9

Native

Answer 9

Folded state

Question 10

Non-native

Answer 10

Unfolded state ( due to heating the molecules in the presence of a detergent )
All molecules have an equally negative charge and denatures them.

Question 11

SDS page

Answer 11

Separates proteins by size alone

Question 12

Isoelectric point

Answer 12

The pH at which a soluble protein has not net charge. Proteins are insoluble at their isoelectric point and so will form a precipitate.

Question 13

Immunoassay techniques

Answer 13

Used to detect and identify specific proteins

Question 14

Monoclonal antibodies

Answer 14

Derived from a single cell line.
Stocks of antibodies with the same specificity.

Question 15

In ELIZA, why are the test wells washed between stages ?

Answer 15

To prevent a false positive result from being obtained.

Question 16

Bright Field Microscopy

Answer 16

Used to observe :

Whole organisms
Parts of organisms
Thin sections of dissected tissue
Individual cells

Question 17

Fluorescence microscopy

Answer 17

Uses specific fluorescent labels to bind to and visualise certain molecules / structures within cells or tissues.

Question 18

Aseptic technique

Answer 18

Eliminates unwanted microbial contaminants when culturing micro-organisms or cells.

Question 19

Broth

Answer 19

Contains suitable nutrients for growth of cells

Question 20

Medium

Answer 20

Contains growth factors from serum

Question 21

Primary cell lines

Answer 21

Divide a limited number of times

Question 22

Haemocytometer

Answer 22

Method used to count cell density

Question 23

Vital stain

Answer 23

Distinguishes living from dead cells
Vital stains only stain dead cells

Question 24

Disadvantages of unsung a haemocytometer

Answer 24

Time consuming
Clumping of cells
Small cells are difficult to locate
Dead cells not distinguished from live unless stained

Question 25

Standard Curve

Answer 25

Used to determine an unknown

Question 26

How to receive a suitable colony count ?

Answer 26

Use serial dilution