title: Microfluidic cell surface antigen expression analysis using a single antibody type.
abstract: Antigen expression plays a significant role in clinical studies, pathology, biology and chemistry. The type and degree of antigen expression can provide information for disease diagnosis/monitoring and is used for phenotype analysis of cells. In this work, an affinity capture method was developed to capture cells based on antigen expression differences in a single microfluidic chip. Microfluidic chips with two affinity regions-at different antibody concentrations-captured two cell types based on differences in the expression of a single antigen. Using herringbone-modified capture channels, a separation purity of 95% and a capture efficiency of 15% were achieved under continuous-flow conditions. We observed that the capture ratio of Ramos B lymphocytes and HuT 78 T lymphocytes matched the expression ratio of CD71 for the two cell lines (R(2) = 0.94). To further validate our analytical method, Ramos B lymphocytes were spiked into blood samples to demonstrate performance with a complex sample. Expression ratios matched conventional flow cytometry measurements over a 40-fold difference, and the sample enrichment was 9.5×. This method has proven to be a robust system to measure the differences in antigen expression, and can be used to distinguish cells without having a unique surface antigen if the expression level is sufficiently high in one cell type.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA. d.pappas@ttu.edu.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA. d.pappas@ttu.edu.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Pappas
mesh_terms: D000906:Antibodies / Q000276:immunology*; D000954:Antigens, Surface / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D045744:Cell Line, Tumor; D002469:Cell Separation / Q000295:instrumentation*; D005786:Gene Expression Regulation; D006801:Humans; D056656:Lab-On-A-Chip Devices
chemical_list: D000906:Antibodies; D000954:Antigens, Surface