Automated long-term monitoring of parallel microfluidic operations applying a machine vision-assisted positioning method.

Hon Ming Yip,Raymond H W Lam,Chi Chiu Leung,Xin Cui,Qiannan Gao,John C S Li,Kai Xie,Agrim Prasad

doi:10.1155/2014/608184

Abstract

As microfluidics has been applied extensively in many cell and biochemical applications, monitoring the related processes is an important requirement. In this work, we design and fabricate a high-throughput microfluidic device which contains 32 microchambers to perform automated parallel microfluidic operations and monitoring on an automated stage of a microscope. Images are captured at multiple spots on the device during the operations for monitoring samples in microchambers in parallel; yet the device positions may vary at different time points throughout operations as the device moves back and forth on a motorized microscopic stage. Here, we report an image-based positioning strategy to realign the chamber position before every recording of microscopic image. We fabricate alignment marks at defined locations next to the chambers in the microfluidic device as reference positions. We also develop image processing algorithms to recognize the chamber positions in real-time, followed by realigning the chambers to their preset positions in the captured images. We perform experiments to validate and characterize the device functionality and the automated realignment operation. Together, this microfluidic realignment strategy can be a platform technology to achieve precise positioning of multiple chambers for general microfluidic applications requiring long-term parallel monitoring of cell and biochemical activities.

Highlights

IntroductionDue to the technology advancements in microfluidics over the past two decades, the applications have extended to cover cell culture [1,2,3,4,5,6], cell analysis [7,8,9,10], drug testing [11,12,13], DNA analysis [14,15,16,17,18], crystallization [19, 20], and liquid chromatography [21]
We introduce the application of micropatterned alignment marks located in a microfluidic device to achieve position control of microfluidics and parallel monitoring of activities in multiple microchambers
We developed a microfluidic position control system capable of implementing microfluidic manipulation and automated image-based microchamber alignment

Summary

Introduction

Due to the technology advancements in microfluidics over the past two decades, the applications have extended to cover cell culture [1,2,3,4,5,6], cell analysis [7,8,9,10], drug testing [11,12,13], DNA analysis [14,15,16,17,18], crystallization [19, 20], and liquid chromatography [21]. The parallel cell applications can be further integrated with programmable components [23,24,25,26] and biosensors to perform real-time sensing abilities (e.g., dissolved gases and cell density measurements) [27,28,29]. Pneumatic valves [30], pumps [30], and mixers [31, 32] are examples of the basic microcomponents which can automate the fluid-handling operations, for example, flow direction and flow rate as well as solution concentration. Gomez-Sjoberg et al developed a fully automated cell culture system on an integrated microfluidic chip which contains 96 chambers with timelapse monitoring [33]. Skafte-Pedersen et al built a programmable microfluidic platform with real-time optical readouts to perform parallel cell culture experiments [34]

Methods

Results

Conclusion