Pipette

These are used to transfer a known volume of liquid from one container to another. They are designed Other to contain (TC) a specific volume of liquid or to deliver {TD) a specified volume.
To contain and To deliver (TC & TD”): Manufacturer stamp TC or TD near the top of the pippet. TC pippet holds or contains a particular volume but does not ‘dispense that exact volume, whereas TD pippet will dispense that exact volume indicated,
TABLE 1-4 PIPET CLASSIFICATION
I. Design
(A)To contain,(TC)
(B)TO deliver(TD)
Drainage characteristics
(A)Blowout
(B)Self-draning

Type
(A)Measuring or graduated
1 Seorologic
2 Mohr
3 Bacteriologic
4.Micropippet

(B). Transfer
1.Volmetric
2. Ostwald-Folin
3. Pasteur pippets
4. Automatic micropippets or micropippets
(Source: Bishop’s Clincal chemistry, 5th Ed)
Blowout and self-draining:

A blowout pippet has continuous etched ring or two small, close continuous rings located near the top of the pippet. This means that the last drop of liquid should be expelled Into the receiving vessel, ‘Without these markings, a pipet Is self-draining, and content of pippet drain by gravity.

Transfer pipettes: It transfers a known volume of liquid without further subdivisions, They include both volumetric and Ostwald.Folin pipettes. They consist of a cylindrical bulb joined at both ends to narrower giaiss tubing. A calibration. mark is etchpd around t hp upper suction tube. The b•re Of deliver’ orifice should be sufficiently narrow to prevent rapid outflow of liquid arid incomplete drainage.
A volumetric transfer pipette is calibrated to deliver accurately a fixed volume of a dilute aqueous solution, Ostwald-Folin pipettes have bulb closer to the delivery tip unlike volumetric pipet which has at center, These (09 are used for accurate measurement of visoous fluids, such as blood or serum, In contrast to volumetric pipet, an Dstwald-Folio pipett has an etched ring near the mount piece, indicating it Is a blow out pipett. With the use of pipetting bulb, liquid is blown out of the pipett only after blood or serum has drained to the last drop In delivery tip. Volumetric pipet are self draining and is used in diluting standards,. calibrators, or quality-control materials,
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Measuring pipettes; These are graduated or measuring pipette and can dispense different volumes as these have many graduations. It has uniform graduations along its length, TWO kinds are the Mohr pipette has graduations ends above the tip and serological pipette has graduated marks down to the tip. mahr pipet is self draining, The serological pipette rnu5T be blown out to deliver the entire volume Of the pipette and has an etched ring or pair of rings) near the bulb end Qf the pipette signifying that it is a blow-out pipette. Serological pipettes have a larger orifice than do the Mohr pipettes and thus drain faster. IVleasuring pipettes are used for the transferring and measurement of reagents and making dilutions and are not considered sufficiently accurate for measuring samples and calibrators, tilicropippet is also a measuring pipet which can measure less than ImL.

filicroplpettes:
These are pipettes to measure micro liter of volume eg 0.1,0,2 rril. Inner wall of pipette can be coated with liquid so most micropipettes are calibrated to contain (It) that stated volume rather than to deliver It
Features of our pipettes:
3. Tips are carefully trotded and ensure privet flow rates alontwith proper tJrnIng
4. Tips edges are fire polish to ensure safety.
5, All pipettes are colour coded at the top to allow fast identification
6_ Symmetrical bulb is ensured in volurnetrit pipettes,
7_ Adequate weight of pipette i5 enSurecl so that breakage while use 15. avoided.
B. All pipettes are properly tested.