High-Throughput Incubation and Quantification of Agglutination Assays in a Microfluidic System

Abstract

In this paper, we present a two-phase microfluidic system capable of incubating and quantifying microbead-based agglutination assays. The microfluidic system is based on a simple fabrication solution, which requires only laboratory tubing filled with carrier oil, driven by negative pressure using a syringe pump. We provide a user-friendly interface, in which a pipette is used to insert single droplets of a 1.25-µL volume into a system that is continuously running and therefore works entirely on demand without the need for stopping, resetting or washing the system. These assays are incubated by highly efficient passive mixing with a sample-to-answer time of 2.5 min, a 5–10-fold improvement over traditional agglutination assays. We study system parameters such as channel length, incubation time and flow speed to select optimal assay conditions, using the streptavidin-biotin interaction as a model analyte quantified using optical image processing. We then investigate the effect of changing the concentration of both analyte and microbead concentrations, with a minimum detection limit of 100 ng/mL. The system can be both low- and high-throughput, depending on the rate at which assays are inserted. In our experiments, we were able to easily produce throughputs of 360 assays per hour by simple manual pipetting, which could be increased even further by automation and parallelization. Agglutination assays are a versatile tool, capable of detecting an ever-growing catalog of infectious diseases, proteins and metabolites. A system such as this one is a step towards being able to produce high-throughput microfluidic diagnostic solutions with widespread adoption. The development of analytical techniques in the microfluidic format, such as the one presented in this work, is an important step in being able to continuously monitor the performance and microfluidic outputs of organ-on-chip devices.

A rotationally focused flow (RFF) microfluidic biosensor by density difference for early-stage detectable diagnosis

“…Also, various methods integrated with a microfluidic channel for streptavidin–biotin complex detection have been investigated 36 – 38 . Chen, Ting-Yang, et al, have developed an electrical detection with thin film transistor-based biosensor integrated with a microfluidic channel by monitoring the current response of biotin and streptavidin.…”

Integration of Droplet Microfluidic Tools for Single-Cell Functional Metagenomics: An Engineering Head Start

“…Other characteristics that are key for the integration of these technologies into biological research include accurate detection of biological products [5] , [11] , [15] , [18] , [19] , [20] , rapid heat transfer and cycling [21] , low-cost [22] , [23] , as well as simple integration with automation, data processing tools [6] , [8] , [18] , [24] , and portable electronic devices [25] .…”

Integration of Droplet Microfluidic Tools for Single-cell Functional Metagenomics: An Engineering Head Start

“…Other characteristics that are key for the integration of these technologies into biological research include accurate detection of biological products [5,11,15,[19][20][21], rapid heat transfer and cycling [22], low-cost [23,24], and simple integration with automation, data processing tools [6,18,19,25], and portable electronic devices [26].…”