Pipettes and Tissue Culture Flashcards

1
Q

What are the 3 types of pipettes?

A

Pipettes
Pasteur pipettes
Micropipettes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe a pipette

A

A plastic of glass tube
Graduated to deliver any amount from 1-25mls
Suction of liquid via bub or pipette aid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe a Pasteur pipette

A

Small, tapered glass tube
Used with a bulb
Used to dispense liquid if volume not critical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe a micropipette

A

Use to dispense small volumes from 1-1000 microlitres

Used with disposable tips

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do you use a micropipette?

A

Depress the plunger to the first stop
Insert the tip into the liquid
Slowly release the plunger to pull liquid into the tip
Dispense by pushing the plunger to the second stop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How should a micropipette be held?

A

Hold vertically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is molarity?

A

The measure of the concentration of a solute in solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is molarity measured in?

A

Moles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are moles?

A

The molecular weight of a substance expressed in grams?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is one mole of a substance?

A

Avogadro’s number of molecules of that substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the weight/volume of a solution refer to?

A

The weight of a solute as a percentage of the volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

For aqueous solutions weight/weight is the same as weight/volume
T/F

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When is volume/volume used?

A

To make a solution of two or more liquids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does a “10X Buffer” mean?

A

You would need to dilute by 10 to get the 1x working concentration

(ie a final volume of 10ml needs 1ml of 10X buffer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the formula for calculating dilution?

A

C1V1=C2V2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the goal of a lowry protein assay?

A

To use known concentrations to generate a standard curve

In order to calculate unknown protein concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the Lowry protein assay?

A

Method involving copper bonding to measure protein concentrations through colorimetric techniques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe what happens in the lowry assay

A

Divalent copper ions form complexes with peptide bonds in the protein under alkaline condition
It is reduced then to a monovalent ion which reacts with Folin’s reagent along with radical groups of tyrosine, tryptophan and cysteine
This forms an unstable product reduced to molybdenum blue
Spectrophotometry used

19
Q

How should a spectrophotometer be used?

A

Calibrate machine to appropriate wavelength
Set to zero with a control
Transfer liquid to cuvette (avoid touching the sides)
Place in spec and shut the lid
Read absorbance

20
Q

What is the purpose of tissue culture?

A

To grow cells and passage them to allow propagation of the cell line

21
Q

How can you continue growth of the cell line in tissue culture?

A

Provide cells with nutrients and a medium to grow in in vitro
This allows division by mitosis by the cells and the population can continue to grow
Until limited by nutrient depletion at which point they can be passaged

22
Q

How many cell types do tissue culture dishes normally contain?

A

One

23
Q

What is a “clone” population of cells?

A

A homogenous population of cells derived from a single parental cell

24
Q

Give examples of applications for cell culture

A

Chemo-resistance testing
Genetic tests
Receptor type recordings

25
Q

What is passaging?

A

Removal of medium and transfer of a proportion of the cells to a fresh growth medium

26
Q

Why does passaging allow more growth?

A

Gives cells more space and fresh medium

27
Q

In which phase do the cells not divide?

A

Lag phase

28
Q

In which phase do the cells grow exponentially?

A

Log phase

29
Q

What does the length of the lag phase rely on?

A

Growth phase of the cell line at the time of subculture and the seeding density

30
Q

What is the role of PBS in tissue culture?

A

To buffer the solution

Reduce amount of Mg2+ and Ca2+ ions

31
Q

What is trypsin?

A

A protease which interferes which adhesion proteins

32
Q

What is the role of EDTA in tissue culture?

A

Reduces Ca2+ and Mg2+ as these normally enhance cell adhesion

33
Q

Why do we want to detach the cells in tissue culture?

A

They cannot be passaged when stuck to bottom of dish

34
Q

What was in the DMEM?

A
10% foetal bovine serum 
Glutamine
1% sodium pyruvate
1% pen/strep
Phenyl red dye
35
Q

What is the purpose of 10% foetal bovine serum in the DMEM?

A

Growth factors and attachment proteins

36
Q

What is the purpose of the pen/strep in the DMEM?

A

To stop contamination

37
Q

What is the purpose of the phenyl red in the DMEM?

A

Indicator

38
Q

Why is PBS used to wash off the media?

A

Trypsin is inhibited by Mg, Ca and FBS in the media

39
Q

Which component of the FBS affects the trypsin binding?

A

Alpha-1-anti-trypsin

40
Q

What is trypsin?

A

A proteolytic enzyme serine protease

41
Q

What is the role of trypsin?

A

Breaking bonds to detach cells from surface

42
Q

What was the %CO2 of the incubator ?

A

5%

Diff per cell type - you get a guide with the cells

43
Q

Why should you always passage your cells a couple of times before you do anything with them?

A

To establish they are healthy and growing ok
Establish no issues with freezing
Bulk up the cell number (not many are frozen)