1
Q
Steps in using the spectrophotometer?
A
- Switch on
- Warm up
- Set Mode
- Set Wavelength
- Blank
- Read Standard/Unknown
2
Q
Uses of centrifuge?
A
- Remove cellular elements from blood (serum/plasma)
- Concentrate cellular elements for microscopic examination
- Remove precipitated protein
- Separate CHON bound/Ab-bound ligand
- Extract solutes from aqueous to organic solvents
- Separate lipid components
3
Q
Types of centrifuge?
A
- Fixed-angle head/Angle-head
- Swinging-bucket type/Horizontal head
- Ultracentrifuge
4
Q
Speed of the centrifuge should be checked at least once every?
A
3 months
5
Q
Used for quality control of centrifuge?
A
- Tachometer
- Strobe light
6
Q
Centrifuge timer should be checked ________ against a reference timer.
A
weekly
7
Q
Centrifuge temperature should be checked when?
A
monthly
8
Q
Centrifuge rpm and minutes?
A
1000-1200 x g , 10 + 5 mins
9
Q
Fixed angle centrifuge is used for?
A
Rapid sedimentation
10
Q
Ultracentrifuge rpm?
A
90,000 – 100,000 rpm (178,000 x g)
11
Q
Parts of a centrifuge?
A
Power switch, timer, speed control, brake, tachometer, alarm, safety latch
12
Q
Temperature of Refrigerated Centrifuge?
A
-15 to 25 degrees C
13
Q
Centrifuge: tubes with tapered bottoms?
A
formation of more compact pellets
14
Q
True or false: In centrifuge, tubes must fit snuggly in the carriers.
A
True
15
Q
What will happen if the top of the tubes protrudes too far?
A
impede rotor
16
Q
In using the centrifuge, you must observe?
A
proper balancing
17
Q
Pipet classification according to design?
A
- To contain
- To deliver
18
Q
Pipet classification according to drainage characteristics?
A
- Blowout
- Self-draining
19
Q
Pipet classification according to type (measuring/graduated)?
A
- Serologic
- Mohr
- Bacteriologic
- Ball, Kolmer, or Kahn
- Micropipet
20
Q
Pipet classification according to type (transfer)?
A
- Volumetric
- Ostwald-Folin
- Pasteur pipets
- Automatic macropipets or micropipets
21
Q
holds a particular volume but does not dispense that exact volume
A
TC (To contain) Pipette
22
Q
calibrated by introducing the exact weight of mercury required to give the desired volume at a specific temperature
A
TC (To contain) Pipette
23
Q
mercury does not wet glass and pipettes calibrated this way will contain but not deliver the stated volume
A
TC (To contain) Pipette
24
Q
dispense the indicated volume
A
TD (To deliver) Pipette
25
calibrated by weighing the volume of water that will flow from them by gravity
TD (To deliver) Pipette
26
rate of delivery must never be hastened by blowing
TD (To deliver) Pipette
27
same as TD pipette but drops remaining at the tip after delivery is blown out to receiving vessel
“To Blow-Out” Pipette
28
an etched ring is seen near the mouthpiece
“To Blow-Out” Pipette
29
the user allows the contents of the pipette to drain by gravity
Self Draining pipette
30
has the greatest degree of accuracy and precision
Volumetric or transfer Pipette
31
designed to dispense one volume c/o further subdivisions
Volumetric or transfer Pipette
32
calibrated to deliver a fixed volume of liquid
Volumetric or transfer Pipette
33
has a bulb between mouthpiece and tip that decreases surface area/unit volume and diminished error from water film
Volumetric or transfer Pipette
34
Is volumetric or transfer pipette self-draining or blowout?
self-draining
35
used in measuring viscous fluids such as whole blood
Ostwald-Folin Pipette
36
measures smaller volume (2.0 mm or less)
Ostwald-Folin Pipette
37
Where is the bulb located in Ostwald-Folin pipette?
has a bulb near the tip
38
Where is the etch mark located in Ostwald-Folin pipette?
ring near mouthpiece
39
used with biologic fluids having a viscosity greater than that of water
Ostwald-Folin Pipette
40
Is Ostwald-Folin Pipette self-draining or blowout?
blow-out pipette
41
used to deliver an amount of liquid contained between two calibration on marks
Graduated or Measuring Pipette
42
Type of pipette wherein the rate of fall of liquid is much too fast.
Serologic Pipette
43
Where is the etched band located in Serologic Pipette?
has an etched band on the suction piece
44
has calibration marks to the tip
Serologic Pipette
45
Is Serologic Pipette self-draining or blowout?
blow-out pipette
46
calibration lies between two marks on the stem
Mohr Pipette
47
no graduations to the tip
Mohr Pipette
48
Is Mohr Pipette self-draining or blowout?
self-draining pipette
49
“To contain” pipette which is calibrated with mercury
Micropipettes
50
Type of pipette wherein the entire content of the pipette must be emptied
Micropipettes
51
used when small amount of blood or specimen is needed (< 1 ml)
Micropipettes
52
no calibration; for biologic fluid w/o specific volume
Pasteur Pipette
53
is by far the most routinely used pipette
Automatic Pipette
54
Automatic Pipette for > 1ml?
Macro
55
Automatic Pipette for < 1ml?
Micro
56
Advantages of Automatic Pipette?
* time savings
* safety
* stability
* ease of use
* increase in precision
* lack of required cleaning
57
tips (contaminated) are often disposable
Automatic Pipette
58
Types of Automatic Pipette?
* Air Displacement
* Positive Displacement
* Dispenser/ Dilutor
59
relies on a piston for creating suction to draw the sample into a disposable tip
Air-displacement pipette
60
the piston does not come in contact with the liquid
Air-displacement pipette
61
operates by moving the piston in the pipette tip or barrel
Positive displacement pipette
62
obtains liquid from a common reservoir
Dispenser/Dilutor
63
Designed for use with air-displacement pipette
Pipette tips
64
Positive displacement pipettes use tips made up of?
straight columns of glass or plastics
65
Steps in using Class A Pipettes?
1. Depress the piston up to the first stop position
2. Tip is placed in the liquid
3. Piston is slowly allowed to rise back to original position
4. Pipet tip is drawn up the sidewall of the vessel
5. Place on the wall of the receiving vessel
66
Quality Control used to verify pipette volume accuracy and precision
Gravimetric and spectrometric method
67
used to compare the reproducibility of brands of pipette tips
0.1% phenol red solution in distilled water
68
cleaning solution for glasswares
Acid dichromate and nitric acid
69
Beakers should be made of glass that is resistant to?
many chemicals used and resistant to heat
70
used for general mixing and reagent preparation
Beakers
71
wide, straight-sided cylindrical vessels and are available in many sizes in several forms
Beakers
72
used to measure volumes of liquids when high degree of accuracy is not essential
Graduated Measuring Cylinders
73
pear-shaped flasks
Volumetric Flasks
74
have one calibration mark on narrow part of the neck
Volumetric Flasks
75
used to contain a specific amount or volume of liquid
Volumetric Flasks
76
Analytical Balance precision is up to?
1/1000 of a gram
77
Types of analytical balance?
manual (mechanical) or electronic
78
Rough or Platform Balance precision is up to?
0.1 gram
79
Examples of Rough or Platform Balance?
1. Torsion Balance - for weighing chemicals
2. Triple Beam Balance - three beams are present in the balance
80
is the process of using centrifugal force to separate the lighter portions of a solution,
mixture, or suspension from the heavier portions
Centrifugation
81
the force required to separate two phases
RCF – relative centrifugal force
82
RCF of centrifuge
1.118x10-5 x r x rpm2
83
Factors affecting RCF of centrifuge?
1. Rotor speed
2. Radius of the rotor
3. Effective path length (depth of the liquid)
84
thermometer for total immersion and partial immersion
liquid-in-glass thermometers
85
method of thermometer immersion for monitoring freezers and refrigerators
Total immersion
86
method of thermometer for heating blocks and water bath
Partial immersion
87
Freezing-point depression osmometers are called?
Thermistors
88
Thermometer calibration
1. NIST SRM® 934 thermometer or a NIST SRM® 1968 gallium melting point cell
2. SRM® 934 --> International Temperature Scale 1990 (ITS-90) at 0° C, 25° C, 30° C, and 37° C
3. Gallium melting point cell --> 25g of very pure gallium metal that has a single fixed melting point at 29.7646° C (as defined by ITS-90)
4. Temperature monitoring devices should be verified for accuracy at 6- or 12-month intervals
CCHM
flashcards
Decks in class (4)
# Cards
