Instruction on using the Pipet Pump (Procedure 5 on page III.6 in the lab manual) If you are not familiar or have never used this type of pipet pump before, you should practice...

Instruction on using the Pipet Pump (Procedure 5 on page III.6 in the lab manual) If you are not familiar or have never used this type of pipet pump before, you should practice using the pump with water before preparing the actual solutions. (i) Check the piston level on the pipet pump. If the piston is not completely lowered (refer to diagram above), turn the dial wheel to lower the piston completely. (ii) While holding the pipet in one hand, gently insert the pipet into the “Pipet insert” of the pipet pump. There is a clear silicon seal inside the pipet insert. Do not jam the pipet into the pump. There should be a good grip between the silicon seal and the pipet. Always use one hand to hold the pipet and the other hand to hold the pipet pump. (iii) Place the pipet into the liquid sample. Slowly turn the dial wheel to raise the piston in the upward direction to draw the liquid into the pipet. There is a greater chance to introduce air bubbles or air gaps if you turn the dial wheel too fast. Be care not to accidentally press the dispensing button while turning the dial wheel. (iv) Continue to turn the dial until the liquid is ABOVE the calibration mark on the pipet. (v) Remove the pipet from the liquid sample (keep the pump attached to the pipet) and wipe the outside of the pipet tip with a paper towel to remove excess liquid. (vi) Place a waste beaker underneath the pipet and slowly turn the dial wheel to lower the piston to adjust the liquid level in the pipet until the bottom of the meniscus touches the calibration marking on the pipet. Note: If you accidentally lower the liquid level to below the calibration mark on the pipet, you can simply place the pipet back into the sample and repeat steps (iii) to (v). (vii) Check to see whether there are air gaps (or air bubbles) within the liquid inside the pipet. If there are air bubbles or air gaps, dispense the liquid back into the liquid sample and repeat from step (i) again. (viii) Dispense the liquid either by pressing (and hold) the dispensing button or simply by removing the pipet pump from the pipet. Do NOT push down the piston to dispense the liquid. Pipet Insert Dispensing Button Dial Wheel Piston