Unit 1.1 - Lab techniques for Biologists

Question 1

Give examples of COSHH

Answer 1

Chemicals
Products containing chemicals
Fumes
Dusts
Vapours
Biological agents

Question 2

What does COSHH stand for?

Answer 2

Control of substances hazardous to health

Question 3

What does PPE stand for

Answer 3

Personal protective equipment

Question 4

Give examples of PPE

Answer 4

Safety glasses
Lab coat
Gloves

Question 5

What does an autopipette allow to be measured

Answer 5

Small volumes of liquid accurately

Question 6

What are burettes used for?

Answer 6

Dispense precise volumes of liquid reagants

Question 7

What happens to burette before it is used

Answer 7

Rinsed with the liquid to be used

Question 8

Where are readings taken from?

Answer 8

Bottom of meniscus

Question 9

What is repeated dilution from a stock solution known as? (regular intervals)

Answer 9

Serial dilution

Question 10

What type of dilution is it if each step is a tenfold dilution?

Answer 10

Log dilution

Question 11

The concentration of a pigmented compound can be quantified using a?

Answer 11

Colorimeter

Question 12

How does a colorimeter work?

Answer 12

Passing a light beam at a specific wavelength through a cuvette containing a sample solution

Question 13

How do you calibrate a colorimeter?

Answer 13

Place a calibration solution(usually distilled water) into a cuvette, place in colorimeter and press calibrate, providing a user with a 0 absorbance reading

Question 14

What is a pH buffer

Answer 14

Solution whose pH changes very little when a small amount of acid/base is added to it (to maintain pH)

Question 15

Give one method to determine the unknown concentration of a solution

Answer 15

Standard curve (titration)

Question 16

What seperates substances out in centrifugation?

Answer 16

Size and density

Question 17

What is the liquid that remains above the pellet called in centrifugation?

Answer 17

Supernatant fluid

Question 18

What does protein electrophoresis seperate proteins based on?

Answer 18

Charge/size

Question 19

Give one form of protein electrophoresis

Answer 19

SDS page

Question 20

Do smaller proteins travel furthur or less than bigger proteins in protein electrophoresis?

Answer 20

Further

Question 21

What does seperation of proteins depend on if native gels are used?

Answer 21

Protein charge and shape

Question 22

What do proteins do at their isoelectric point?

Answer 22

Overall neutral charge, precipitate out of solution

Question 23

What charge do proteins carry below their isoelectric point?

Answer 23

Positive

Question 24

How does isoelectric focusing work?

Answer 24

pH gradient is set up on gel:
Protein loaded in and moves until it reaches its isoelectric point where it forms a band

Question 25

What is Chromatography?

Answer 25

Set of Techniques which separate the components of a mixture

Question 26

What are the three types of chromatography?

Answer 26

Paper, thin-layer & affinity chromatography

Question 27

What is the stationary phase in paper chromatography?

Answer 27

Strip of chromatography paper

Question 28

What is the stationary phase in thin layer chromatography?

Answer 28

Strip of absorbent paper such as silica gel

Question 29

What does affinity chromatography rely on?

Answer 29

Binding interactions of protein and a ligand

Question 30

Where is the protein found in affinity chromatography?

Answer 30

Immobilised by specific receptor (ligand)

Question 31

What is immunoassay?

Answer 31

Test which uses antibodies to detect the presence and concentration of a protein within a solution

Question 32

What does immunoassay rely on

Answer 32

Specificity of antibodies

Question 33

What allows scientists to detect when binding has occurred in an immunoassay test?

Answer 33

Each antibody must be linked to a detectable label

Question 34

What does a reporter enzyme do?

Answer 34

Causes a colour change in the presence of a specific antigen

Question 35

What does ELISA stand for?

Answer 35

Enzyme linked immunosorbent assay

Question 36

What is an ELISA?

Answer 36

Analytical technique which uses antibodies to detect the presence of an antigen in a solution

Question 37

What are three types of ELISA?

Answer 37

Direct, Indirect, Sandwich

Question 38

What is the difference between direct and indirect ELISA?

Answer 38

Direct - Primary antibody binds to antigen and has a reporter protein on it Indirect - Primary antibody binds to antigen then secondary antibody binds with a reporter enzyme

Question 39

What happens during Sandwich ELISA?

Answer 39

Capture antibody bound to surface of multiwell plate Antigen is added and allowed to bind Primary antibody added and binds Secondary antibody, linked to a reporter enzyme added and binds to primary antibody

Question 40

Give examples of uses of ELISA

Answer 40

Detection of HIV Detection of food allergies Screening for certain types of drugs

Question 41

What does Protein Blotting allow?

Answer 41

Identify specific proteins seperated by gel electrophoresis

Question 42

What is the first step in protein blotting?

Answer 42

Proteins are separated using gel electrophoresis and transferred to a membrane

Question 43

How is the membrane probed for the protein of interest?

Answer 43

Using a specific antibody linked to a detectable label

Question 44

Give examples of applications of protein blotting

Answer 44

Identify specific proteins which are present in a cell sample Detection of HIV and hepatitis B

Question 45

What does Fluorescence microscopy allow?

Answer 45

Particular protein structures to be visualised

Question 46

What is a fluorescent molecule?

Answer 46

One which absorbs a specific wavelength of light then emits a different (longer) wavelength

Question 47

How does Fluorescence microscopy work?

Answer 47

Specific proteins have fluorescent markers added to them Cells then placed on a slide Protein structures visualised using a fluorescence microscope

Question 48

What does a haemocytometer allow?

Answer 48

Estimation of the concentration of cells in a sample to be made

Question 49

What border can cells be touching to be counted?

Answer 49

Top and right border

Question 50

What can the reliability of a glass haemocytometer be effected by?

Answer 50

Incorrect placement of the cover slip

Question 51

Give a benefit of disposable haemocytometers?

Answer 51

Limit exposure to infectious materials

Question 52

Give examples of things a typical culture media contains

Answer 52

Water Salts Amino Acids Vitamins Glucose

Question 53

What do all animal cell cultures require?

Answer 53

Media containing growth factors

Question 54

Where do the growth factors come from?

Answer 54

Serum

Question 55

What is the inoculum?

Answer 55

Cells that have been used to inoculate culture media

Question 56

What are antibodies?

Answer 56

Y shaped proteins produced by B lymphocytes as part of the immune response

Question 57

What are antibodies used for?

Answer 57

Detect and Identify specific proteins

Question 58

What does fluorescent labelled protein blotting allow a scientist to identify?

Answer 58

Specific proteins that were seperated using gel electrophoresis

Question 59

What is fluorescent Immunohistochemical Staining?

Answer 59

Used to visualize distribution of specific cellular components in live cell

Question 60

What does separation rely on if non native gels are used in protein electrophoresis?

Answer 60

Size

Question 61

State two types of biological material that can be viewed by bright field microscopy

Answer 61

Thin sections of tissue - Parts of an organism

Question 62

How are cells detached from tissues for cell lines?

Answer 62

Using proteolytic enzymes