1.1 : lab techniques for biologists Flashcards

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1
Q

what is a risk assessment

A

a risk assessment is done before every experiment and identifies control methods to minimize the risk of hazards

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2
Q

what are some control methods

A

PPE, appropriate techniques, protective clothing, aseptic techniques

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3
Q

what are some lab hazards

A

toxic and corrosive chemicals, heat, flammable substances, pathogens, mechanical equipment

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4
Q

what is a dilution series

A

an important lab technique tat reduces the concentration of a substance within a soloution

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5
Q

what is linear dilution

A

soloution that differs by an equal interval
e.g. 0.1, 0.2, 0.3

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6
Q

what is log dilution

A

soloution that differs by a constant proportion
e.g. 10-1, 10-2, 10-3

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7
Q

what can a dilution series make easier

A

allows easier counting of colonies when added to an agar plate

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8
Q

what is a colorimeter

A

used to measure the absorbance of a specific wavelength and can be used to quantify the concentration and turbidity of a solution

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9
Q

IEP charges

A

neutral at the isoelectric point
positive below the isoelectric point
negative above isoelectric point

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10
Q

what is formed by isoelectric points

A

a precipitate

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11
Q

what is a isoelectric point

A

is the pH at which a soluble proteins has no net charge which allows the separation of a proteins

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12
Q

how does native electrophoresis separate a protien

A

separates by size,shape and charge as it does not denature the molecule

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13
Q

how does SDS-page electrophoresis separate a protien

A

sds-page denatures molecules giving all a negative charge this means they must be separated by size

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14
Q

what is gel electrophoresis

A

seperation technique which seperates protiens and nucleic acids based on shape size and charge

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15
Q

what is centrifugation

A

a separation technique that is used to separate substances by density by spinning a substance at a high speed which allows most dense substances to form a pellet and least dense to remain suspended in supernatant

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16
Q

what is a pH buffer

A

used to control pH allowing the addition of an acid or alkali to a solution to have little effect

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17
Q

what is a standard curve

A

graph of a known plotted concentration that is used to determine an unknown concentration

18
Q

what is turbidity and how is it determined

A

the cloudiness of a solution and the percentage of transmission of the colorimeter is used to determine turbidity

19
Q

how is a colorimeter calibrated

A

by a cuvette containing distilled water being used as a blank

20
Q

what is affinity chromatography?

A

relies on binding action, a ligand is immobilized within a column and a protein mix is passed through this column, the target protein binds to the complementary ligand and remain in the column while the rest is washed out, results in a pure sample of target protein

21
Q

what is thin layer chromatography?

A

method that uses a stationary phase of absorbent material such as silica, the solvent moves through the stationary phase and travels slow or fast based on solubility.

22
Q

what is paper chromatography?

A

stationary phase is a strip of chromatography paper, mixture is placed at bottom of paper then in solvent, the solvent travels up paper and carries the mixture at different rates due to properties. in this case nonpolar substances usually travel further

23
Q

what are immunoassay techniques?

A

techniques that use monoclonal antibodies to identify proteins

24
Q

what is monoclonal?

A

substance derived from a single molecule..

25
Q

what is a reporter enzyme

A

used as a chemical label and can produce a color change.

26
Q

what are some examples of chemical labels

A

reporter enzymes, chemiluminescence, fluorescence radioactivity

27
Q

what is the IEP process

A

a solution is buffered to a specific pH, A precipitate will then form due to pH of a protein

28
Q

how can gradient gel seperate a protien

A

used by electrical field and gradient gel, mixture stops migrating through gel at IEP as it will have no net charge

29
Q

what is western blotting

A

process used after SDS-page, it separates proteins from gel by blotting it onto a medium and it is then probed for target proteins

30
Q

fluorescence microscopy

A

fluorescent labels are used to bind and visualize particular proteins, the molecule absorbs specific wavelength then releases another this allows the structure to be visualized.

31
Q

what is bright field microscopy

A

this is commonly used for observation; a sample is mounted on a slide and is illuminated from below. The light is then transmitted through the specimen to the o objective lens and to the eyepiece. the samples are then often stained for comfort.

32
Q

what are aseptic techniques?

A

eliminates microbial contamination and is vital for a successful cell culture.

33
Q

examples for aseptic techniques

A

sterile equipment, good personal hygiene, clean work area, counting microbial cells.

34
Q

what is cell culture

A

is the growth of cells in an inoculum on an agar medium or in a broth flask, the process requires control of factors which promote growth of specific cell types

35
Q

what is a growth factor

A

usually a serum, used in animal cell culture that promote cell growth and proliferation.

36
Q

what is a haemocytometer

A

equipment used to estimate cell number in a liquid cultrue, it has a counting chamber known as liquid volume and can estimate concentration

37
Q

what is vital staining

A

stains cells which are required to identify and count viable cells.

38
Q

what is direct ELISA

A

an antigen binds to the surface of a well . a antibody linked with a reporter enzyme then binds also the the antigen

39
Q

what is indirect ELISA

A

an antigen bind to the surface of a well , a primary antibody is then added also to the well and binds with the antigen, a secondary antibody is also added linked with a reporter enzyme to the primary antibody

40
Q

what is sandwich ELISA

A

a capture antibody is added to the well, the antigen is then added and binds to the antibody. a primary antibody is added to the well and then a secondary antibody linked to a reporter enzyme binds to the primary antibody

41
Q

what is ELISA

A

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