Study on the Air-Tightness Detection System for Pipetting in the Automated Aptamer Selection Instrument

Abstract

Aptamers are a new kind of nano-probes for bioassays and drug delivery, etc. The good air-tightness is important for pipetting to achieve the purpose of the quantitative liquid distribution in the automated aptamer selection instrument. The pipette tip will be worn and torn after the long-term use, which may result in the leakage, reduction in liquid volume or even pipetting failure. The goal of this study is to constantly detect whether the gas path in the automated aptamer selection instrument leaks during pipetting. The air-tightness detection system is designed according to the change of the air pressure when sucking and discharging liquid. In this study, a hardware system was built to detect air pressure in the gas path of the instrument during the pipetting process, and data processing algorithm was designed to judge if the air pressure curve was normal which included differential processing and detection of extreme points within the threshold. The air-tightness detection model can accurately detect the air-tightness in the pipette during the suction and discharge process to ensure the stable operation of the aptamer selection. This system can also be used for air-tightness detection of other equipment.