pipettes presentation for Laboratory experts

1. PIPETTES
By:
Wali Khan
Lab Technologist
PPHRL Quetta

2. What are Pipettes?
• A slender tube attached to or incorporating a bulb, for transferring or
measuring out small quantities of liquid, especially in a laboratory.

3. Types of pipettes:
Five grades of pipettes includes..
• Disposable/ Transfer pipettes
• Graduated/serological pipettes
• Single channel pipettes
• Multichannel pipettes and
• Repeat pipettes
• Electronic Pipettes

4. Disposable/ Transfer pipettes
• The most basic pipettes.
• It is not sophisticated Equipment of laboratory.
• Used for rough estimation.
• Disposed after usage.
• Very important because its follow the standard pipetting techniques.
• Aspirate liquid at a 90-degree angle and dispense at a 45-degree
angle.
• Make sure that all the liquid is dispensed.

5. Graduated/Serological Pipettes
• Using of this type of pipette, the final volume is found by calculating
the difference of liquid level before and after dispensed.
• Standard technique for using graduated pipette
Uses:
Used for high amounts of measurements.
• Hold pipette in solution. Don’t touch the bottom.
• Squeeze the bulb and attach to the top of the pipette.
• Hold forefinger on the top of the pipette to control the volume
aspiration.
• Subtract the amount needed into a separate beaker while staying eye
level to assure proper measurement.
• Measure the solution from the bottom of the meniscuses.

6. • Subtract needed volume from the initial volume and find the volume
needed to release to in order to get desired amount.

7. Single Channel Pipette:
• Also known as Micropipette.
• Non deposable device.
• Air-displacement designed which used for accurate measurement of
liquids and reagents in microliters to 1 milliliter.
• Required disposable tips for their measurements
• Very sensitive to use.

8. Two common techniques
• Forward technique
• Reverse technique

9. Forward Technique:
• The most common technique for pipette measurement.
• Press the plunger to the first stop and slightly submerge the pipette
tip into the liquid, release the plunger slowly to prevent bubbles.
• To dispensed the liquid, place the tip against the side of receptacle,
then slowly press the plunger through the first stop to the final blow.

10. Reverse Pipetting Techniques:
• When working with viscous solution or to aspirate bubble solution we
have the option to use this technique.
• This technique will minimize interference from air bubbles.
• Press the plunger all the way to 3rd stop position slightly submerge
into the liquid and slowly release the plunger.
• Aspirate the liquid into the tip, place the pipette against the
receptacle wall and press the plunger to the first stop, holding the
plunger in place and remove the tip from the receptacle.
• Now You will have a sample liquid that remain in the tip but it is not
the part of the measurement.

11. Multichannel Pipette:
• The technology and techniques behind this pipette is similar to that of a
single channel except it takes more than one tip at a time. Since liquid is
aspirated at the same time from the small well into the multiple channel,
you must ensure the aspirated liquid level are equivalent then it
dispensed into the plate well.
Uses:
• Install of the proper tips to each channel and set the desired volume.
• Hold the pipette in vertical position depress the plunger to the first stop.
• Immerse the tip into the liquid and release the plunger to back to the rest
position.
• Place the tips at a45 degree against the vessel and push the plunger to the
2nd stop to expel all the liquid to the vessels.

12. Repeat Pipette dispenser:
• This type of pipette allow a lab worker to set and dispense a specific volume
into multiple receptacles without having to aspirate in between dispenses.
This multi-dispensing capability saves time and effort.
• It has a different design than the typical pipette.
• The difference is a filling and dispensing lever as opposed to a plunger.
• To use to a repeater pipette successfully.
Uses:
• Slide the filling lever down as far as it goes.
• Raise the locking clamp upward.
• Insert the syringe type tip into the barrel so that it click into the position
then close the lever.
• Immerse the tip into the liquid at a 90 degree angle.

13. • Slowly slide the filling lever upward to fill the tip completely.
• Prime the tip by discarding the liquid from the first dispense
• The repeating pipette is now ready to operate.
• Accuracy and repeatability are two most important aspects of testing
with pipettes.

14. Electronic Pipettes
• Electronic pipettes are ideal tools in the Laboratory.
• Where the accuracy of your results, speed and ergonomics are
important.
• Their fully electronic control guarantees consistent, user-independent
results, and their lightweight, ergonomic design gives you total
convenience.
• With their multiple pipetting modes, you may perform your liquid
handling tasks faster than with mechanical pipettes.
• Many applications in laboratories today require the pipetting of very
small amounts of liquid – just a few microliters, exactly and
repeatedly.
• Electronic pipettes ensure high accuracy and precision, by
significantly reducing human variance.

16. Features of an Electronic Pipette

17. Air Displacement Pipette
• An air displacement pipette is a common laboratory tool used to
handle a measured volume of liquid between 1 µl to 1000 µl (1 ml).
Due to its high accuracy, this laboratory tool is commonly used in
standard pipetting applications.
• The piston moves to the appropriate position when the volume is set.
• When the operating button is pressed to the first stop, the piston
expels the same volume of air as indicated on the volume setting.
• After immersing the tip into the liquid, the operating button is
released.

18. Pipetting Error
1. Not accounting for the Viscosity of a sample
A sample that contain large and sticky molecules.
2. Dispensing the Liquids too quickly.
3. Contamination by “Double Dipping”.
4. Cleaning Irregularly- or not at All.
5. Taking a break only at the end of the work.

19. Any Question……..??
THANKS