First Grading Flashcards
required for preparation of any primary standard.
Analytical balances
Single pan enclosed by sliding transparent doors.
Analytical balances
Uses an electromagnetic force to
counterbalance the weighed sample’s sample.
Electronic balances
Consists of a head or rotor, carriers, or shields that are attached to the vertical shaft of a motor or air compressor and enclosed in a metal covering
Clinical centrifuge
process in which centrifugal force is used to separate solid matter from a liquid suspension; also separate two liquid phases of different densities.
Centrifugation
RCF in grams=
1.118 x 10-5 x r x (rpm)2 ; or use nomogram
RPM =
tachometer or strobe light TYPES: 1.
tubes placed in the cups of the rotor assume a horizontal plane when the rotor is in motion and vertical position when at rest.
Horizontal-head or swinging-bucket centrifuge
During centrifugation, particles travel in a constant manner along the tube while the tube is at right angle to the shaft of the centrifuge.
Horizontal-head or swinging-bucket centrifug
Angle-head or fixed angle centrifuge
Tubes are held at a fixed angle from
25-40 degrees to the vertical axis of rotation.
Particles are driven outside and bottom of the tube and the surface of the sediment packs against the side and bottom of the tube and the surface of the sediment is parallel to the shaft of the centrifuge.
Angle-head or fixed angle centrifuge
- High-speed centrifuge; mainly fixed angle rotorsq
- requires a refrigerated chamber
Ultracentrifuge
circulating or noncirculating.
Water bath
Water bath maintenance
Type II (or Type I)
water
MEASURING DEVICES: PIPETS
Classification According to Graduations
Graduated or Measuring Pipets
C. “Blow Out”
D. “Between Two Marks”
Transfer pipets
Volumetric pipets
Ostwald-folin pipet
Pasteur pipet
Automatic pipet
used to transfer aqueous solutions & non-viscous samples self-draining
Volumetric pipet
has the greatest degree of accuracy and precision
Volumetric pipet
read at the lower meniscus
Volumetric pipet
bulb at the center
Volumetric pipet
used for biologic fluids having viscosity greater than water; blowout pipet
Ostwald folin
read on the upper meniscus
bulb is closer to the delivery tip
Ostwald folin
no calibration mark; used to transfer solutions or biologic fluids without consideration of a specific volume
Pasteur piper
Graduated or Measuring Pipets
Mohr pipet
Serological pipet
calibrated between two marks; deliver between their calibration marks
Mohr pipet
- Tip should NOT touch the receiving vessel
- self-draining; with smaller orifice
Mohr pipet
graduated down to the tip
Serological pipet
blow-out pipet; with larger orifice
Serological pipet
exact volume is calibrated to fill the volume between two calibration points on the pipet
Between Two Marks
Holds the particular volume but
does not dispense the exact
volume
To-Contain” (TC)
Requires rinsing calibrated with
mercury usually a micropipette - Volumes are expressed in microliter
“To-Contain” (TC)
Delivers the exact volume indicated; Calibrated for the volume delivered fluid is allowed to flow freely with the pipet tip touching the inner wall of receiving vessel
“To-Deliver” (TD)
Safer, less time consuming, precise & convenient
Automatic macropipets or micropipets
Automatic macropipets or micropipets
THREE GENERAL TYPES :
Air dispacement
Positive displacement
Dilutor/dispenser pipet
relies on a
piston for suction creation to draw the sample into a disposable tip.
Air-displacement:
operates by moving the piston in
the tip or barrel.
Positive displacement
Sample enters directly upon
contact without air interference. - NO need to replace delivery tip
Positive displacement
obtain the liquid from a common reservoir and dispense it repeatedly; combines sampling & dispensing functions
Dilutor/Dispenser pipets
CALIBRATION methods
Gravimetric
Spectrophotometric
has a round, lower portion with with a flat bottom and a long, thin neck with an etched calibrated line.
Volumetric Flask
For preparation of standards for quantitative procedures.
Volumetric Flask
cylindrical shaped calibrated plastic or glass containers.
Centrifuge Tube
Cuvets
- 13mm x 100mm
- Constant light path: 1 cm distance
Cuvets
TYPES as to COMPOSITION: Contain acidic solutions
Soft
Cuvets
TYPES as to COMPOSITION:
Alkaline solutions
Hard
TYPES as to WAVELENGTH SETTINGS
GLASS
wide-range settings
(300–700nmor380–700nm)
TYPES as to WAVELENGTH SETTING QUARTZ
short wavelength
settings (UVR: below 340 nm)
TYPES as to SHAPE
Glass
Round
TYPES as to SHAPE
Square
Quartz/plastic
transfer of smaller volumes (<500ul) in blood gas analyis or separation techniques (chromatography, electrophoresis).
SYRINGES
SPECIAL GLASSWARES:
Colored and Opal Glasses
Coated Glass
Optical Glass
Glass Ceramics
Radiation-Absorbing Glass
has a thin, metallic oxide permanently fire-bonded to its surface; can conduct electricity
Coated Glass
has metallic oxides; used for
filters and light bulbs
Colored and Opal Glasses
made of soda lime, lead and borosilicate
Optical Glass
has a high optical activity; prisms, lenses and optical mirrors
Optical Glass
with high thermal resistance, chemical stability and corrosion resistance
Glass Ceramics
Glass Ceramics are used for
hot plates, table tops and heat exchangers
made of soda lime and lead
Radiation-Absorbing Glass
Clear and rigid; not autoclavable
POLYSTYRENE (PS)
Used for disposable wares
POLYSTYRENE (PS)
Polyethylene
Not recommended for use with
acids, aldehydes, ketones, ethers,
hydrocarbons or essential oils.
POLYSTYRENE (PS)
Chemically resistant to most substances except for aldehydes, amines, ethers, hydrocarbons and essential oils
POLYETHYLENE
translucent and flexible; not autoclavable
Conventional Polyethylene (CPE):
Translucent and rigid; autoclavable;
POLYPROPYLENE (PP)
Has the same chemical resistant as polyethylene
POLYPROPYLENE (PP)
Used for screw-cap closures
POLYPROPYLENE (PP)
Resin that has excellent chemical resistance to almost all chemicals in the lab.
Teflon
Clear, translucent and flexible; autoclavable
TEFLON
Used for stopcocks, wash bottles and tubings
Teflon
Translucent and flexible; autoclavable
Tygon
used for tubings
TYGON
Very susceptible to damage by most chemicals.
POLYCARBONATE (PC)
Resistant to water, aqueous salts and inorganic acids for a long period.
POLYCARBONATE (PC)
Very clear and rigid; autoclavable
POLYCARBONATE (PC
Used for most bottles and tubings
POLYVINYL chloride (PVC)
Used for carboys, test tube racks
POLYCARBONATE (PC)
