LABORATORY MATERIALS AND INSTRUMENTATION Flashcards
Used to separate substances of different mass or density
CENTRIFUGE
RPM stands for
revolutions per minute
RCF stands for
relative centrifugal force
formula for RCF
RPM2 x r x 1.12 x 10-5
RPM of the centrifuge is calibrated using _____
tachometer
Swinging bucket type, the centrifuge tubes are held in a vertical position when not moving but are horizontal when the centrifuge is fully in motion
Horizontal head centrifuge
Centrifuge recommended for SST
Horizontal head centrifuge
Has a fixed 25-52 degrees angle in which the tubes are held during centrifugation
Angle Head Centrifuge
Centrifuge adequate for cell packing
Angle Head Centrifuge
Generates the highest speed; centrifuge head is held at a fixed angle but generates tight sediment buttons due to the high speed generated
Ultracentrifuge
Centrifuge for lipoprotein separation
Ultracentrifuge
Pipets are classified according to:
According to design, drainage, and purpose
Holds a particular volume but does not dispense the exact volume
To contain
Will dispense the exact volume indicated
To deliver
Last drop of the liquid should be expelled into the receiving vessel to get the exact volume
Blow out / Blown Out
Allows the contents of the pipet to drain by gravity
Self- draining pipet
It is a self-draining pipet but the tip should not be allowed to touch the vessel while the pipet is draining
Mohr Pipet
Has a graduation marks to the tip and is generally a blowout pipet
Serologic Pipet
It is a pipet with a total holding volume of less than 1 mL
Micropipet
Used for biological fluids with viscosity greater than that of water (such as blood)
Ostwald Folin Pipet
What type of pipet is Ostwald Folin Pipet
Blow out pipet
It has the greatest degree of accuracy and precision
Volumetric Pipet
Most commonly used mechanical pipet which relies on piston for suction
Air displacement pipet
A mechanical pipet that operates by moving the pistol in the pipet/barrier
Positive displacement pipet
Plastic pipet is made of ____
Polypropylene
Calibrating media for TD and TC pipet
TD: distilled water
TC: mercury
Wavelength is ____ proportional to amount of energy
inversely
<400 nm
UV
> 700 nm
infrared
Absorbance is ___proportional to the concentration
directly
Light source for visible - infrared range
tungsten halongen / iodide lamp
MC used light source
tungsten halogen lamp (1200 nm)
Light source for ultraviolet range
mercury arc lamp, deuterium discharge lamp, xenon arc lamp
Function of entrance slit
Minimizes the unwanted or stray light
It isolates specific or individual wavelengths
monochromator
Give (4) examples of monochromator
colored glass filters, prisms, interference filters, diffraction grating
wedge shaped pieces of glass, quartz or NaCl
Prisms
most commonly used due to better resolution than prisms
Diffraction gratings
Controls the width of light beam (bandpass)
Exit Slit
Holds the sample solution
Sample Cuvette
Which is more preferred when it comes to the bottom of cuvette? Round or square
Square
Convert the transmitted energy into an equivalent amount of electrical energy
detector
Has excellent sensitivity and rapid response
Photomultiplier tube
Fluoremetry is a.k.a _____
Molecular luminescence spectrophotometry
Principles of fluoremetry
- It measures the amount of light intensity present over a zero background
- Determines the amount of light emitted by a molecule after excitation by EM radiation
Things to remember about fluorometry:
Things to remember about fluorometry:
- Uses 2 monochromator
- Monochromator is set at a right angle
- Uses a UV light source
- More sensitive and more specific (500-1000x more sensitive than spectro)
referes to presence of other substance that could interfere fluorescence
Quenching Phenomenon
Stokes effect refers to the difference between ___. ____, ______.
maximum wavelength, excitational, and emitted fluorescence
