Science basics: Measuring volumes precisely with pipettes

Examine why measuring cylinders cannot measure volumes smaller than 1 milliliter and explain the need for alternative tools when precise small-volume measurements are required in chemistry.

Attach a pipette filler to a color-coded graduated pipette by holding both objects near the ends and pushing firmly to create a secure seal. Avoid holding the pipette too low to prevent accidents.

Fill the graduated pipette to the zero mark at the top of the scale, then release liquid using the side lever until reaching the desired volume mark, accounting for the reversed scale orientation.

Calculate the starting mark by subtracting the desired volume from the pipette's total capacity, then fill to that mark to obtain the precise small volume needed.

Attach a pipette filler to a volumetric pipette set for a specific volume such as 25 milliliters, then draw liquid up to the calibration line on the narrow neck to achieve high precision measurements.

Attach a disposable tip to a micropipette, set the dial on top to the desired volume such as 20 microliters, then draw up the exact volume needed for precise minute measurements.

Review the differences in measurement precision and appropriate applications for graduated pipettes, volumetric pipettes, and micropipettes based on the volume range and accuracy required.