Intelligent Pipetting System Towards Automatic Liquid Handling Applications

Automation of life sciences and pharmaceutical laboratories is high on demand in the present day, especially with the emergence of high throughput screening and drug discovery. Lab automation provides reliable and efficient solutions, limiting reagent amounts with increased throughput and reduced costs. In this work, we present an affordable, intelligent, sub-microlitre resolution automatic pipetting system. This system employs a differential pressure sensor to detect most frequently occurring pipetting errors in automatic liquid handling workstations, which include no liquid sample present in the source well, pipette tip not attached to the holder, clogging of the tip, aspiration of air bubbles or foam, insufficient liquid in the source well, improper dispensing of the samples and tip not intact with the holder. This also determines liquid volumes aspirated into the pipette tip, providing a self-validating mechanism for the system, thereby reducing human intervention and improving performance efficiency. A prototype system was developed in-house and gravimetric analysis was carried out to determine system performance. Repeatability coefficient of variation for the designed system was found to be below 5.5% for the volume range of 10 to 200 microlitres, while the error obtained was observed to be less than 1.6%. Experimental tests conducted could flawlessly detect mentioned pipetting abnormalities through the algorithm designed.