Lecture 1 Flashcards
Types of pipettes
Pasteur
Serological (less contamination)
Transfer (squeezey thing)
Air displacement Pipette (normal one)
Air displacement puppets have what types of tips
Disposable
Need to be tight on the pipette
What are the steps to using the air displacement pipette
Decrease to the required volume
Prepare for aspiration (push to the first stop)
Aspirate sample (keep pipette vertical , keep tip just under surface of liquid)
Dispense Sample (onto the side of the vessel, angle the vessel not the pipette, push down all the way to dispense)
What are the steps to using the air displacement pipette
Decrease to the required volume
Prepare for aspiration (push to the first stop)
Aspirate sample (keep pipette vertical , keep tip just under surface of liquid)
Dispense Sample (onto the side of the vessel, angle the vessel not the pipette, push down all the way to dispense)
To set the volume on the pipetteman classic what do you do
Pass the required volume by 1/3 of a turn then decrease to the required voljme
What is the minimum and max of
p20
P200
P1000
It’s it better to use p20 for 20microl or p200?
2-20microl
20-200
100-1000
P20 because the error is less if you use the smaller pipette
1ml of water had mass of
1g
What is a good error
+/- 1%
What is the types of water you can use in measurements
Deinoized water
Treated with UV light (destroys the organic compound in the water)
Filtered water (removes particle bigger then 0.1micrometer
Sterilized water (for molecular biology)
Reverse osmosis water
What is a fixed angle rotor
A swing out rotor
Types of centrifuge where the tube are at and angle so the pellet forms at the sides
Spin horizontally and The force goes directly down the tubes, pellet forms at very bottom
What is the equation for force when there is angular acceleration
F=mw^2r
W is the angular frequency in radians per second
R is the radius from the centre of rotation
What is relative centrifugal force
Conparing the angular acceleration to gravity
So. : w^2r/g
g is 9.81m/s^2
What is angular acceleration
Since F=ma
And F=mW^2r
a=w^2r
Is it better to use relative centrifugal force or just centrifugal force
Relative since the radius is diff across labs
Slide 15 angular acceleration calc
Okay
Why is the force at the top of a fixed angle rotor centrifuge different from the force at the bottom?
Because the radius at the top is different than the bottom due to the angle
Example of a fixed angle rotor
Give important trait of it
SS-34
Angled at 34 degrees
What is the pH in cells
7.2
What do we need to know to make a buffer
The buffering soecies
The total concentration of the buffering soecies
The pH
Hh equation
Pka= ph + log A-/HA
Slide 20 calc
Okay I’m lab book
What are good buffers
MES, HEPES, tris
Their pka ranges from 6.15 to 8.3
What do buffers actually do
The working by gaining or losing protons
