Pipets Flashcards
Used to transfer measured volumes of liquid between containers
PIPETS
Highly pigmented/colored/opaque (viscous) liquid =
upper meniscus
Colorless/transparent liquid =
lower meniscus
Pipets are classified based on:
Design
Drainage characteristics
Type
Design
A. To contain (TC)
B. To deliver (TD)
Drainage characteristics
A. Blowout
B. Self-draining
2 types of pipet
A. Measuring or graduated
B. Transfer
A. Measuring or graduated
- Serologic
- Mohr
- Bacteriologic
- Ball, Kolmer, or Kahn
- Micropipet
B. Transfer
- Volumetric
- Ostwald-Folin
- Pasteur pipets
- Automatic macropipets or micropipets
AKA, “Rinsed-out pipets”
To contain (TC)
Must be refilled and rinsed-out with the appropriate solvent after the initial liquid has been drained from the pipet
To contain (TC)
used for dosing the blood which is to be examined.
Quantification of hemoglobin
Sahli-hemoglobin pipets
TC or TD
Sahli-hemoglobin pipet
TC
TC or TD
Long-Levy pipets
TC
Designed to drain by gravity
To deliver (TD)
Must be held vertically with the tip placed against the side of the container and must NOT TOUCH the liquid in it
To deliver (TD)
TC or TD
Serologic
TD
TC or TD
Mohr
TD
TC or TD
Volumetric transfer pipet
TD
A_____ pipet holds or contains a particular volume but does not dispense that exact volume, where as a_____ pipet will dispense the volume indicated.
TC
TD
Must be held vertically with the tip placed against the side of the container and must NOT TOUCH the liquid in it
Exemptions: 2
Serologic and Mohr pipet
______– calibration marks may be confined to the stem.
With a______, they may extend to the tip.
Mohr pipet
serologic pipette
Graduated to the tip
Serological pipet
Not graduated to the tip
Mohr pipet
S or M
Exact 10ml
Serological
S or M
No excess
Serological
S or M
Calibration mark = 9ml
Serological
S or M
Blown out pipet
Serological
S or M
TD
Serological
S or M
Has excess ml
Mohr
S or M
Self draining
Mohr
S or M
Apply pressure
Mohr
S or M
To contain
Mohr
Self-draining or blowout
With a single paint at the top
Self draining
Self-draining or blowout
Drain by gravity
Self draining
Self-draining or blowout
No
- frost
-etch
-double lines
Self draining
Self-draining or blowout
Not graduated to the tip
Self draining
Self-draining or blowout
With
- double ring
- frost
- etched
Blowout
Self-draining or blowout
Designed to be blown out by pushing a small amount of air out of the pipet, completely emptying it
Blowout
Self-draining or blowout
Graduated to the tip
Blowout
Used to measure and transfer a predetermined volume of liquid.
Volumetric/Transfer Pipet
Dispense one volume without further subdivisions
Volumetric/Transfer Pipet
Volumetric/Transfer Pipet
Self draining except:
Ostwald-Folin
Pasteur
Used for viscous fluid
Blowout
Ostwald-Folin
Not good for quantitative analytic techniques; for transferring liquids
Not considering specific volumes
Medicine dropper-like
Pasteur
Capable of holding a volume greater than 1mL but only one determined volume can be dispensed
Automatic Pipet
The volumetric pipette are always
SELF-DRAINING
Ostwald-Folin pipette are______ (used with biologic fluids having a viscosity greater than that of water)
BLOWN OUT PIPETS
The bulblike enlargement in the pipet stem easily distinguishes the
Ostawd-Folin.
Calibrated to distribute fractional quantity of liquid and principally used for measurements of reagents
Measuring or Graduated pipet
NO graduations to the tip
Self-draining
Mohr Pipet
Has Graduation marks to the tip
Generally a blown out pipet
Serologic
With a total holding volume of less than 1 mL
It may be designed as either a Mohr or serologic pipet
MICROPIPETS
Commonly used in the laboratory
Dispense on volume without subdivision (transfer pipet)
Also, it can dispense several different volumes just like a measuring pipet
Automatic and Semi-automatic pipet
2 TYPES OF MICROPIPETTE
Air displacement
Positive displacement
Micropipette
Both are____ operated
piston
AIR DISPLACEMENT
Disposable,______ tip
polypropylene
Relies on a piston for creating suction to draw the sample into a disposable tip that must be change after each use
AIR DISPLACEMENT
Piston does not come in contact with the liquid
AIR DISPLACEMENT
Form aerosis that can easily escape the pipet
AIR DISPLACEMENT
POSITIVE DISPLACEMENT
Use of_____ tip
capillary
(siliconized, glass, plastic)
Operates by moving the piston in the pipet tip or barrel, much like a hypodermic syringe
POSITIVE DISPLACEMENT
Does not require a different tip for each use
POSITIVE DISPLACEMENT
Piston comes in contact with the liquid
POSITIVE DISPLACEMENT
- Where we operate to displace the liquid (push button)
PLUNGER
- Press to eject the pipet tip and is connected to the tip ejector
TIP EJECTOR BUTTON
- Allow us to set the volume of liquid to be displace
THUMBWHEEL
- Shows the volume set to displaced
VOLUMETER DISPLAY
pushed in order to aspirate or dispense a particular volume of sample or reagent
PUSH BUTTON
Not going push it but turn it bcs it is going to serve as a large volume adjustment knob
In order to adjust the volume to be aspirated in much more larger amounts
PUSH BUTTON
Simply push this down to remove the pipette tips that is found at the bottom portion
TIP EJECTOR BUTTON
Used to adiust the volume to be aspirated in smaller amounts
THUMBWHEEL (FINE VOLUME ADJUSTMENT RING)
Where u are able to determine how much of the solution or what is the exact volume to be aspirated, transferred or measured
VOLUMETER DISPLAY
Connected to the shaft
Simply push to move and lead to the removal of your disposable tip
TIP EJECTOR
: mainly for the draining of the entire solution that was aspirated in the pipet tip
Second stop
Automatic pipette that obtain the liquid from a common reservoir and dispense it repeatedly may be bottle-top, motorized, or attached to a dilutor.
Dispensers and dilutor/dispensers -
Although it allows us to have an easier measurement of volumes of samples and reagents, but the aspiration and dispensing of such liquids can still be done manually
Semi-automatic pipettes
It is attached to a machine and a tube is going to be submerged to a particular solution
The machine will be regulating the aspiration as well as the dispensing of a particular volume of a reagent ot sample
Automatic pipettes
Automatic pipettes that obtain the liquid from a common reservoir and dispense it repeatedly
May be bottle top, motorized, handheld, or attached to a dilutor
Dispensers (Dilutors)
