Bio-contaminated plastic micropipette tip sterilization stations: Environmentally, economically, and energetically viable solution

Abstract

Bioscientific research laboratories significantly contribute to global plastic waste production through their use of plastic products, such as single-use micropipette tips. Biologically contaminated pipette tips must undergo several washing and sterilization steps before being reused or recycled. There is a dearth of available research studying the feasibility of pipette tip washing and sterilization in research laboratories. While automated tip-washing systems are available commercially for tip decontamination and reuse, the high initial purchasing cost of these washing stations and concerns related to washing efficiency deter many research laboratories from incorporating them. To mitigate these concerns, considering the University of Texas at Austin as an example, we performed a cost-benefit analysis of employing a university-wide pipette tip washing station. We estimated that only a single-time reuse of pipette tips could result in a 100% return on investment from the equipment. Additionally, preliminary analysis shows that pipette tip recycling can result in significant energy and water savings. With pilot experiments, we replicated UV-based decontamination steps employed by the commercial equipment and found the washing to be 100% efficient in sterilizing pipette tips contaminated with bacteriophage, DNA, and RNA. Decontaminated pipette tips were used to conduct phage quantification to demonstrate the feasibility of reuse for biological assays. Finally, we proposed an alternative autoclave-based sterilization method that can be used in individual research labs to decontaminate pipette tips. We found autoclave-based washing to be 100% efficient in sterilizing pipette tips contaminated with bacteriophage, whereas it is not efficient enough to decontaminate DNA and RNA.