Using a pipette pump, such as with a serological pipette, involves a few key steps to accurately and safely transfer liquids. The following outlines the general procedure, incorporating details from the provided reference.
Steps for Using a Pipette Pump
Here’s a breakdown of how to effectively use a pipette pump:
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Preparation: Ensure you have the correct size pipette for your desired volume. Attach the pipette securely to the pipette pump.
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Aspirating Liquid:
- Gently press the S (or suction) valve located directly below the bulb of the pipette pump. According to the reference, press the valve until the pipette is filled just above your desired volume. This is crucial for accurate measurements.
- Control the suction to avoid drawing liquid too quickly into the pipette.
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Dispensing Liquid:
- To dispense, use the appropriate dispensing valve on the pipette pump. The specific valve will vary depending on the type of pump.
- Allow the liquid to drain naturally from the pipette tip. You can touch the pipette tip to the receiving vessel to ensure complete dispensing, if necessary, depending on your protocol.
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Zeroing/Setting Meniscus:
- If you over-aspirated, use the exhaust valve to bring the meniscus down to the precise graduation mark that you need.
Additional Tips for Accurate Pipetting
- Vertical Positioning: Hold the pipette vertically to ensure accurate volume readings.
- Meniscus Reading: Read the meniscus (the curve of the liquid) at eye level. For most liquids, read the bottom of the meniscus.
- Practice: Consistent and accurate pipetting requires practice.
- Cleanliness: Keep your pipettes and pumps clean to avoid contamination and ensure accurate measurements.
