Option 3

Dr Smith: ‘Emma, this is not actually your real issue here but, you’ve stumbled upon a different common error. The angle of the pipette during aspiration is critical; if it drifts too far from vertical, it can indeed lead to inaccurate volumes being drawn up—either too much or too little.

When you’re aspirating, ensure that the pipette is held vertically, directly above the liquid. This ensures that you’re pulling the correct volume into the tip. Then, when you’re ready to dispense, maintain a controlled slight angle, around 30 degrees, and touch the side of the receiving vessel. This technique helps ensure that all the liquid is transferred, minimizing residual drops inside the tip. Keeping these angles consistent is key to enhancing your pipetting accuracy. Let’s give it another try keeping these adjustments in mind.’

Go to: 

Option 1: Emma is likely releasing the plunger too quickly during aspiration, which can cause air bubbles to form in the tip and lead to inconsistent volume uptake (e.g 1050 μL).

Option 2: Emma is likely submerging the pipette tip too deeply, causing liquid to be drawn into the tip due to increased pressure differences or capillary action.