According to regulatory standards, pipette calibration laboratories must keep their relative humidity at greater than 50%. Working laboratories are often significantly drier, though. By visiting Olympic National Park, Artel sought to determine how pipettes behave in a humid environment and whether varying humidity levels affect pipetting accuracy and precision.
Tools and Technique
The team conducted four experiments and in each, used a number of variable-volume pipettes from leading manufacturers that dispense a maximum of 1,000, 200, 20, and 2 µL. During the experiment, each pipette was used to dispense 10 data points, each at its maximum and minimum volumes.
Volume accuracy and precision of the pipettes were tested in the extreme environment using the company’s PCS® Pipette Calibration System. The PCS is based on ratiometric photometry, which measures the absorbance of light of proprietary reagents at two distinct wavelengths to verify volume. The change in the absorbance at each wavelength is measured to calculate the actual volume pipetted. The system automatically compares actual dispensed volumes to desired target volumes and quantifies any resulting error.
Understanding the Effect
In an environment such as the Olympic National Park, both temperature and humidity must be evaluated to truly understand resulting volume variability.