Split injection: A simple introduction of subnanoliter sample volumes for chip electrophoresis

A. Gáspár, P. I. Koczka, H. Carmona, F. A. Gomez

Research output: Contribution to journalArticle

14 Citations (Scopus)


The ability to accurately inject small volumes of sample into microfluidic channels is of great importance in electrophoretic separations. While electrokinetic injection of nanoliter scale volumes is commonly utilized in microchip capillary electrophoresis (MCE), mobility and matrix bias makes quantitation difficult. Herein, we describe a new injection method based on the simple patterning of the crossing of channels that does not require sophisticated instrumentation. The sample volume injected into the separation channel is dependent on the ratio of the widths of the crossing channels. This injection method is capable of introducing, into a separation channel, multiple plugs of sample on a large scale. This injection technique is tested for zone electrophoresis in native and surface modified poly(dimethylsiloxane) (PDMS) chips.

Original languageEnglish
Pages (from-to)180-185
Number of pages6
JournalMicrochemical Journal
Issue number2
Publication statusPublished - Nov 1 2011



  • Chip
  • Chip electrophoresis
  • Poly(dimethylsiloxane)
  • Pressure injection

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy

Cite this