High-Throughput Separation Assay for NO Metabolites in Blood Using Microfluidic Electrophoresis

摘要

As an alternative NO assay based on the Griess method, we investigated a high-throughput separation assay of NO_2~- and NO_3~-in human blood using an electrophoretic Lab-on-a-Chip with UV detection directly. To measure the NO metabolites in real human blood, we optimized the running buffer condition of an on-chip pre-concentration technique, transient isotachophoresis (tITP) and also applied voltages for a new dry-etched quartz glass chip in microfluidic sample-introduction and separation. We achieved acceptable sensitivity for the rapid NO metabolite separation assay with 6.5 seconds and 25 seconds for separation and sample introduction, respectively. As a result for the tITP application, the limits of detection for NO_2~- and NO_3~- in human pooled serum were improved to be 2.3 μM from 5.0 μM and 9.1 μM from 14.2 μM, respectively.