Get 2 Great Ways of Pipetting
Pipetting, the most basic operation in a lab, probably one of the first things that you learn in the laboratory, it seems simple, but still need a lot of practice to get all the volumes correctly, especially with difficult sample types.
Following is two most common ways of pipetting : forward pipetting and reverse pipetting.
Forward pipetting
This technique is suitable for almost every occasion, highly recomended for low-density solution, such as salt solutions, nucleotide solutions, volatile compounds like methanol,buffers, acids, alkalis and even radioactive compounds. It is the most common way of pipetting.
Details steps are as follow:
1. Press the volume adjustment knob to first stopping point.
2. Slowly release the knob to the starting point to complete aspiration.
3. Press the knob gently again to its first stopping point to complete dispensing.
4. Wait for a moment, before continuing to press the button to the second stopping point to drain the liquid completely.
5. Release the knob back to starting point. If necessary, replace the pipette tip before continuing with pipetting.
Reverse pipetting
This technique is suitable for viscous liquid or volatile liquid, such as protein and nucleic solutions, oily solutions like glycerol and surfactant mixes like Tween. It is less used, but very important when you deal with these specific type of samples, even body fluids like whole blood or serum, if high accuracy is required.
Details steps are as follow:
1.Press the volume adjustment knob to second stopping point for aspiration.
2.Slowly release the button to the starting point to complete suction.
3.Aspirate more liquid than the set volume.
4.Gently press the knob to the first stopping point to dispense liquid of set volume.
5.Discard the residual liquid left in the pipette tip.
And last tip for you, please do every step slowly and gently.