Explorations of ABO-Rh antigen expressions on erythrocyte dielectrophoresis: Changes in cross-over frequency

Document Type

Article

Publication Date

9-2011

Department

Department of Chemical Engineering

Abstract

A quadrupole dielectrophoretic microdevice was utilized to examine the ABO-Rh dependencies on erythrocyte polarizations. This important step toward medical microdevice technology would transform key clinical blood tests from the laboratory into the field. Previous work in dielectrophoretic microdevices demonstrated that the large number of ABO antigens on erythrocyte membranes impacts their dielectrophoretic signature at 1MHz. This work explores the dielectrophoretic behavior of native human erythrocytes categorized by their ABO-Rh blood types and directly compares these responses to the same erythrocyte sample modified to remove the A and B antigens. A β(1-3)-galactosidase enzyme was utilized to cleave the ABO polysaccharide backbone at the galactosidase bonds. The enzymatic reaction was optimized by comparing agglutination of the native and modified blood cells in addition to UV-Vis and HPLC analysis of the reaction effluent for saccharide residues. Next, the dielectrophoretic behaviors of the native and modified erythrocytes were visually verified in a quadrupole electrode microdevice over a frequency range from 100kHz to 80MHz. The lower cross-over frequency (COF), which transitions from negative to positive dielectrophoresis, for ABO blood types tested (A+, A-, B+, B-, AB+, O+ and O-) differed over the range from 17 to 47MHz. The COFs of the corresponding enzyme-modified erythrocytes were also determined and the range narrowed to 29-41MHz. A second COF in the 70-80MHz range was observed and was reduced in the presence of the transmembrane Rhesus factor. These results suggest that antigen expression on erythrocyte membrane surfaces influence cell polarizations in nonuniform AC fields.

Publication Title

Electrophoresis

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