A-12
Appendix
Special care should be taken to avoid liquid being aspirated into the interior
working of the pipet. Push and release the push button slowly at all times,
particularly when working with high viscosity liquids. Never allow the push
button to snap back. Make sure that the tip is firmly attached to the tip
cone. Check for foreign particles in the tip.
• Do not touch pipet tip with bare fingers. Risk of contamination is
possible. Use powder free gloves for protection.
Before you begin your actual pipeting work, fill and empty the tip 3 to
5 times with the solution that you will be pipeting. Hold the pipet in an
upright position while aspirating liquid. The grippy should rest on your
index finger. Make sure that the tips, pipet and solution are at the same
temperature.
Fill a clean reservoir with the liquid to be dispensed.
1. Depress the push button to the first stop.
2. Dip the tip under the surface of the liquid in the reservoir to a depth
of about 1 cm and slowly release the push button. Withdraw the tip
from the liquid, touching it against the edge of the reservoir to remove
excess liquid.
3. Deliver the liquid by gently depressing the push button to the first stop.
After a delay of about one second, continue to depress the push button
all the way to the second stop. This action will empty the tip.
4. Release the push button to the ready position. If necessary, change the
tip and continue pipeting.
Pipet Techniques
General
Forward Technique
