Measurement of Carcinoembryonic Antigen in Clinical Serum Samples Using a Centrifugal Microfluidic Device.

Zhigang Gao,Xiaorui Li,Tingjiao Liu,Yao Lu,Jiu Deng,Bingcheng Lin,Lingling Xu,Zongzheng Chen,Yueyang Qu,Weijie Zhao,Yong Luo

doi:10.3390/mi9090470

Abstract

Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker used in clinical applications. The primarily clinical method for measuring CEA is based on chemiluminescence in serum during enzyme-linked immunosorbent assays (ELISA) in 96-well plates. However, this multi-step process requires large and expensive instruments, and takes a long time. In this study, a high-throughput centrifugal microfluidic device was developed for detecting CEA in serum without the need for cumbersome washing steps normally used in immunoreactions. This centrifugal microdevice contains 14 identical pencil-like units, and the CEA molecules are separated from the bulk serum for subsequent immunofluorescence detection using density gradient centrifugation in each unit simultaneously. To determine the optimal conditions for CEA detection in serum, the effects of the density of the medium, rotation speed, and spin duration were investigated. The measured values from 34 clinical serum samples using this high-throughput centrifugal microfluidic device showed good agreement with the known values (average relative error = 9.22%). These results indicate that the high-throughput centrifugal microfluidic device could provide an alternative approach for replacing the classical method for CEA detection in clinical serum samples.

Highlights

Carcinoembryonic antigen (CEA) is a polysaccharide-protein complex with a molecular weight that ranges from 180 to 220 kD, and has 28 potential N-linked glycosylation sites
The sample was mixed with a detection cocktail consisting of silica microbeads (1 μm diameter), which were coated with specific antibodies for the target of interest, in this case, CEA
A centrifugal microfluidic chip was constructed for detecting CEA in clinical serum samples

Summary

Introduction

Carcinoembryonic antigen (CEA) is a polysaccharide-protein complex with a molecular weight that ranges from 180 to 220 kD, and has 28 potential N-linked glycosylation sites. The serum concentration of CEA can become elevated in the presence of several types of cancer, such as lung [1,2], breast [3,4], colorectal [5,6], or gastric [7] cancers, as well as colon adenocarcinoma [8]. A wash-free one-step immunoassay [14] was developed using a centrifugal microfluidic device, which has great potential for use in clinical applications. This immunoassay method is based on the principle of centrifugal density gradient equilibrium, which takes place inside a microfluidic device. Afterwards, the fluorescence microbeads, which aggregated at the end of microchannel, could be collected for quantitative analysis

Methods

Results

Conclusion