This study compared the performance of new and reconditioned pipette tips in a Human TNF-α ELISA assay. P1000 and P200 tips were contaminated with a Human TNF-α reconstituted standard and reconditioned using our process. 5 standards were prepared according to the manufacturer’s dilution scheme (Millipore, EZHTNFA-150K). The assay followed the incubation and reagent addition steps specified in the associated protocol. Absorbance readings were measured at 450 nm and 590 nm, and the optical density (OD) was calculated as the difference of absorbance between the two wavelengths. Standard curves were constructed for both new and reconditioned tips to compare and analyse their absorbance readings and tendencies
Additionally, quality control samples were included to validate the efficiency and functionality of the assay. The standard curves generated were used to determine the concentrations of these controls, enabling a comparison of the performance of new and reconditioned tips for unknown standard concentrations.
This experiment allowed us to assess the accuracy of reconditioned tips in an ELISA assay.
Results
The standard curves obtained from new and reconditioned tips had very similar trendline equations. Furthermore, the concentrations of the quality controls determined using the standard curves for both new and reconditioned tips were comparable and fell within the range specified by the kit. This indicates that the reconditioned tips contained no residual standard.
Conclusion
Our process operated in a way that allows the use of reconditioned tips in highly sensitive experiments such as an ELISA assay.