Unit 1 Lab Techniques

Question 1

Define affinity

Answer 1

The degree to which a substrate is attracted and tends to bind to another

Question 2

Define affinity chromatography

Answer 2

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

Question 3

Define an antigen

Answer 3

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

Question 4

Define aseptic technique

Answer 4

Procedures in place to prevent contamination including sterilising equipment and work surfaces

Question 5

Define bright field microscopy

Answer 5

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

Question 6

Define a buffer

Answer 6

A solution used to set and maintain a particular pH

Question 7

Define centrifugation

Answer 7

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

Question 8

Define a chromatography

Answer 8

A technique used to separate different substances; it has a stationary phase that the mobile phase moves through, carrying the substance being examined; different distances are moved by substances of differing solubilities

Question 9

Define a colorimeter

Answer 9

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

Question 10

Define a culture media

Answer 10

A nutrient rich gross medium providing their basic requirements for cell growth (amino acids glucose salt water as well as specific growth factors for animal cell lines)

Question 11

Define fluorescence

Answer 11

The emission of light of different wavelengths to that which was absorbed

Question 12

Define fluorescence microscopy

Answer 12

A microscopy technique that uses specific fluorescent labels to bind and visualise certain molecules or structures within cells or tissues

Question 13

Define gel electrophoresis

Answer 13

A technique used to separate samples of nucleic acid and proteins by size; introduced to a gel they move through it due to an electric current smaller fragments travel further than larger fragments

Question 14

Define growth factors

Answer 14

Proteins that promotes cell growth and proliferation

Question 15

Define a haemocytometer

Answer 15

Microscopic grid used to estimate the total number of cells within a sample (originally used to count red blood cells)

Question 16

Define a hazard

Answer 16

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

Question 17

Define immunoassay

Answer 17

Technique used to detect and identify specific proteins; antibodies linked with reporter enzymes e.g. calls a colour change in the presence of specific antigen

Question 18

Define inoculum

Answer 18

Starting material used to grow a culture from for example a bacteria cell culture

Question 19

Define Isoelectric point (IEP)

Answer 19

The pH at which a soluble protein has no net charge and will precipitate out a solution

Question 20

Fine linear dilution series

Answer 20

A series of delusions that differ by a constant proportion

Question 21

Define log dilution series

Answer 21

A series of solutions that differ by equal intervals

Question 22

Define monoclonal antibodies

Answer 22

Stocks of identical antibodies that are specific to a particular antigen

Question 23

Define native gel electrophoresis

Answer 23

Does not contain SDS And is not denature proteins so proteins are separated by sheet size and charge

Question 24

Define pathogenic

Answer 24

Causing disease

Question 25

Define primary cell lines

Answer 25

A culture of sells ice deleted directly from an animal or plant tissue they have an infinite lifespan and expansion capacity

Question 26

Define reporter enzymes

Answer 26

An enzyme linked to an Ab specific to a protein antigen they are used and immunoassay techniques

Question 27

Define SDS page

Answer 27

Electrophoresis in which gel contains SDS which gives all molecules and equally negative charge and denatures them separating proteins by size alone

Question 28

Define serum

Answer 28

Vitally important as source of growth factors hormones leopards and minerals for culture cells

Question 29

Define standard curve

Answer 29

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

Question 30

Define supernatant

Answer 30

The liquid that lives above a solid residue are Pella in the centrifugation

Question 31

Define 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

Define vital staining

Answer 32

A technique In which a harmless die is used to staying in their living tissues are dead cells for Microscopical observation to allow viable cell count to be made

Question 33

Define western blotting

Answer 33

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

Question 34

What is the difference between a typical culture media and a complex culture media

Answer 34

A typical culture media contains what are salts amino acids vitamins and glucose Complex culture media has growth factors that promote so growth and proliferation

Question 35

Describe the process of western blotting

Answer 35

The proteins are transferred from a sale to a solid medium The membrane is blocked to prevent antibodies from binding to the wrong part of the membrane Antibody is added and then washed off A secondary label antibody is added and then washed off Results are obtained by chemiluminescence

Question 36

Explain the difference between absorbance transmission and turbidity

Answer 36

Turbidity is a degree to which a fluid loses its transparency due to the presence of suspended particles in suspension Absorbance the quality of light absorbed by solution Transmission is the quantity of light that passes through a solution

Question 37

Why is fluorescent labelling of antibodies useful

Answer 37

Fluorescent labelling for antibodies allows for visualising proteins Sensitive At low concentrations are stable over long periods of time and do not interfere with the function of the target molecules

Question 38

How and why is brightfield microscopy carried out

Answer 38

A sample is mounted on a slide and illuminated from bellow Samples are staying before viewing using a Brakefield my scope to increase contrast contrast Used to examine whole organisms/parts of them

Question 39

How and why is present field microscopy carried out

Answer 39

Is used image specific features of small specimens such as microbials Use a specific for us and labels to bind and visualise certain molecules

Question 40

What is the haemocytometer used for

Answer 40

It is accounting chamber device originally designed and used for counting blood cells

Question 41

Why would you use tumour cell lines instead of primary cell lines for culturing cells

Answer 41

Tumour cells can perform unlimited divisions (immortal sales) whereas primary cells die after certain amount of divisions (mortal cells)

Question 42

Name the components of a complex culture media required by animal cells were they used for

Answer 42

Proteins that promote self growth and proliferation | Use for the cultivation of bacterial pathogens and other fastidious bacteria

Question 43

Why is vital staining used to estimate viable cell count

Answer 43

Viable stealing allowed viable sells beer then divide and Celko to be before him where as only answered in sales are counted as die is only taking up by dead cells

Question 44

Give three health and safety considerations for procedures

Answer 44

Where are your hair up Wear goggles Where lab coats

Question 45

Give a brief message for linear and log dilutions

Answer 45

Lock delusions measure a range of solutions that differ five constant for portion each solution access the stock for the next Linear delusions differ by equal intervals and add measures of volume to the stock solution

Question 46

Why are standard curves used

Answer 46

As a standard glass can be used to determine the concentration of an unknown sample

Question 47

Why are buffers used

Answer 47

To keep the pH of a reaction constant

Question 48

How do you calorimeters work and why are they used

Answer 48

A colorimeter is used to measure the quantity of like the sample absorbs it transmits operate by passing a beam of light through a sample and measuring the light intensity reaching the detector

Question 49

How does the centrifugal separate materials

Answer 49

I love separation of materials to the use of a rotor that spins in a centrifuge a centrifugal force is applied to each particle the sample the particle will then sediment at the rate that the rate proportional to the force that was applied

Question 50

Describe both methods and purpose of protein electrophoresis

Answer 50

Native jealous every proteins by their size shape and charge they do this by ensuring they do not denature the molecule SDS drill separate proteins by size alone proteins are heated in the presence of a detergent

Question 51

Describe the method and purpose of isoelectric focusing

Answer 51

A pH gradient is that up alone a tube of gel using a special offer a mixture and then electrical field is applied

Question 52

Describe how are use immunoassay to diagnose conditions such as HIV

Answer 52

An antibody test checked for antibodies to the HIV virus the enzyme like with a Venus absorbent is ELIZA which is used for the detection of HIV antibody and antigen If the antigen is present the antibody binds if the substrate is added and a colour change this suggests HIV virus

Question 53

Name three types of chromatography and briefly describe the methods and purposes

Answer 53

Paper separation of mixtures based on their solubility is the speed this all your travels along the chromatograms depends on at solubility Thin-layer chromatography is the same except it’s performed on a sheet of glass or plastic which is coated with a layer of absorbing material usually gel or Celulose Infinity chromatography separate target proteins are a mixture soluble target proteins in a mixture will become attached to them as the mixer passed down the column molecules with no affinity are washed out target protein move from the column