1.1 laboratory techniques

Question 1

affinity

Answer 1

the degree to which a substance is attached and tends to bind to another

Question 2

affinity chromatography

Answer 2

a technique used to separate and purify proteins based on a specific binding interaction between an immobilised ligand and its binding partner

Question 3

antigen

Answer 3

a specific protein with which antibodies can bind in an immune response

Question 4

bright-field microscopy

Answer 4

microscopy commonly used to observe whole organisms, parts of organisms, thin sections of dissected tissue or individual cells

Question 5

aseptic technique

Answer 5

procedures in place to prevent contamination, including sterilising equipment and work surfaces

Question 6

buffer

Answer 6

a solution used o set and maintain a particular pH

Question 7

centrifugation

Answer 7

a process that used centrifugal forces to separate components of different densities in a mixture

Question 8

chromatography

Answer 8

a technique used to separate different substances; it has a stationary phase (paper or gel) that the mobile phase (solvent) moves through, carrying substance being examined; different distances are moved by substances of different solubility

Question 9

colorimeter

Answer 9

a device used to measure the absorbance of a specific wavelength of light by a solution

Question 10

culture media

Answer 10

a nutrient-rich medium providing the basic requirements for cell growth

Question 11

fluorescence

Answer 11

the emission of a different wavelength to that which was absorbed

Question 12

fluorescence microscopy

Answer 12

microscopy technique that uses specific fluorescent labels to bind to and visualise certain molecules or structures within a cell or tissue

Question 13

gel electrophoresis

Answer 13

technique used to separate samples of nucleic acid and protein by size; introduced to a gel, they move through it die to an electric current; smaller fragments move further than larger fragments

Question 14

growth factors

Answer 14

proteins that promote cell growth and proliferation

Question 15

haemocytometer

Answer 15

microscopic grid used to estimate the total number of cells within a sample

Question 16

hazard

Answer 16

anything that poses a potential risk or threat to an individual or the environment

Question 17

immunoassay

Answer 17

technique used to detect and identify specific proteins; antibodies linked with reporter enzymes, for example, cause a colour change in the presence of a specific antigen

Question 18

inoculum

Answer 18

starting material used o grow a culture form, for example a bacterial culture

Question 19

isoelectric point (IEP)

Answer 19

the pH at which a soluble protein has no net change and will precipitate out of solution

Question 20

linear dilution series

Answer 20

a series of dilutions that differ by an equal interval, for example 0.1M, 0.2M, 0.3M and so on

Question 21

log dilution series

Answer 21

a series of dilutions that differ by a constant proportion

Question 22

monoclonal antibodies

Answer 22

stocks of identical antibodies that are specific to a particular antigen

Question 23

native gel electrophoresis

Answer 23

des not contain SDS and does not denature the molecule, so proteins are separated by their shape, size and charge

Question 24

pathogenic

Answer 24

causes disease

Question 25

primary cell lines

Answer 25

a culture of cells isolated directly form animal or plant tissues; they have finite lifespan and limited expansion capacity

Question 26

reporter enzyme

Answer 26

an enzyme linked to an antibody specific to a protein antigen; they are used in immunoassay techniques

Question 27

SDS-PAGE

Answer 27

electrophoresis in which the gel contains SDS, which gives all the molecules an equally negative charge and denatures them, separating proteins by size alone

Question 28

serum

Answer 28

vitally important as a source of growth factors, hormones, lipids and minerals for the culture of cells

Question 29

standard curve

Answer 29

a graph that can be used to determine the concentration of an unknown solution

Question 30

supernatant

Answer 30

the liquid that lies above a solid residue or pellet in centrifugation

Question 31

turbidity

Answer 31

a measure of the degree to which a fluid loses its transparency due to the presence of suspended particles or cells in suspension

Question 32

vital staining

Answer 32

a technique in which a harmless dye is used to stain either living tissue cells or dead cells for microscopical observation to allow a viable cell count to be made

Question 33

western blotting

Answer 33

an analytical technique used to identify and locate specific proteins in a sample of tissue homogenate or extract based on their ability to bind to specific antibodies