1.10.24basic Flashcards
Centrifugal force depends on 3 variables…and separates based on…
mass, speed, radiusdensity
speed expressed as…force generated express as…or…angular velocity value…r=
revolutions/min(rpm)relative centrifugal force/RCF or gravity (g)1.118x10*-5r=radius in cm from center of axis to bottom
Equation for speed of centrifuge related to RCF/RCF=
1.118x10-5 x r x (rpm)’210 to neg 5*2=squared
CLSI
clinical and lab standards institute
CLSI recommend blood be centrifuged at an RCF of…or…for…min
1,000-1200xgOR3500 rpm for 10-15 min
…or… centrifuge where tubes are horizontal position when spinning and in a vertical position when stopped
Horizontal head or swinging bucket
…or…centrifuge where tubes are at angle in sample bucket, allowing small particles to sediment faster
fixed angle or angle head
Centrifuges that separate small liquid samples of <=2mL in plastic conical shaped containers w/integral snap cap
microcentrifuges
High speed centrifuge up to 150,000rpm to separate chylomicrons from serum
ultracentrifuge
strobe light determines…
speed
Check speed of centrifuge with…or….every…
tachometer or strobe light, every 6mths
NIST
national institute of standards and technology
Check time with…timer, every…
NIST traceable timer, 6mths
centrifuge used to sediment small particles faster
fixed angle/angle head
centrifuge used to separate chylomicrons from serum
ultra
Glassware/plasticware must fall into class…or….Institute that recommends tolerance limits…Preferred glassware class…Usually made of… …
Class A, BNIST recommendedPreferred is A and made of borosilicate glass
Pipette that is electronic, prepare multiple samples…Pipette that are handheld, disposable tips w/air displacement or positive displacement
Automatic pipettesemi-automated pipette
Mechanism of action which relies on a piston for creating suction to draw the sample into a disposable tip that’s changed after useA certain volume of air remains between the piston and the liquid.
air displacementie. pipettes used in lab
Mechanism of action which has a moving piston in pipepette tip or barrel much like a hypodermic syringe, doens’t require a different tip and is used as a dispenser.The piston is in direct contact with the liquid.
Positive displacmentie. osmo pipette
Which pipete requires recalibration…how often per year…Two methods used to calibrate…
automatic pipettes, 4x/yrgravimetric and volumetric
Calibration that verifies accuracy by the amt of water dispensed by pipette. Weight of water is proportional to the volume dispensed.Weight=volume
Gravimetric
Calibration that verifies accuracy of amt of dye thats pipetted into a specific volume of water and is read spectrophotometrically.absorbance=amount
volumetric
Which class of glassware doesn’t need to be recalibrated
A
Handheld that require bulb to apply suction
manual