PIPETTES Flashcards
Type i classification
A. To deliver
B. To contain
Type I classification where water is used for calibration
to deliver (TD)
Type I classification where Hg is used for calibration
To contain (TC)
Classification according to drainage characteristic
TYPE II
Type II classification
a. to blow out pipet
b. Self draining
information in blow out pippettes
- frosted band/two thin rings
- thicker colored rings
Type III classification
a. measuring or graduated pipets
b. Transfer pipets
has calibration marks to the tip and is generally a blow-out pipet
serologic
does not have graduations to the tip
Mohr
may either be a serological or mohr, calibrated either TC or TD. with total holding volume of less than 1 mL
micropipet
Printed on the neck of the pipette are the specifications
that indicate:
- maximum volume
- size of division on the pippete
- temp at which calibrations are made
- TD or TC
colorless liquid meniscus
lower
dark colored miniscus
upper
Designed to dispense one volume
Transfer pipets
types of transfer pipetes
- Volumetric
- Ostwald-Folin Pipet
- Pastuer pipet
- Automatic pipets
Has a cylindrical bulb located midways between the mouth and the tip
Volumetric
has the greates accuracy and precision
Volumetric
deliver a single specific volume of liquid, usually
between 1 and 10 ml
Volumetric
used for accurate measurement & other nonviscous fluids
Volumetric
bulb is located closer to the
delivery tip
Ostwald-Folin Pipet
with an etched ring/blow-out pipet
Ostwald-Folin Pipet
used to measure viscous fluid
Ostwald-Folin Pipet
have no calibration marks and are used to transfer solutions or biologic fluids without consideration of a specific volume.
Pasteur pipet
most routinely used
Automatic pipets
has a pipetting capability of less than 1 ml
Micropipet
dispenses greater than 1 ml
Automatic macropipet
3 General Types of Automatic Pipets:
- Air Displacement
- Positive Displacement
- Dispensers and Dilutors
relies on a piston for suction creation to draw the sample into a disposable tip that must be changed after each use.
Air Displacement
operates by moving the piston in the pipet tip or barrel, much like hypodermic syringe.
Positive displacement
Does not require different tip for each use. Requires rinsing and blotting
between samples to prevent carryover.
Positive Displacement
automatic pipets that obtain the liquid from a common reservoir and dispense it repeatedly.
Dispensers and Dilutors
The dispensing pipets may be bottle –top, motorized, handheld or attached to a dilutor
Dispensers and Dilutors
