Local reagent synthesis in microfluidics

The ability to generate reagents for miniaturized analytical devices in situ leads to many important gains. Device complexity decreases as the number of fluid inputs is reduced. Reagent quantity can be tuned in real time to reach a desired sensed output. Additionally spatial control of reactions is achieved by controlling reagent synthesis positions. As a proof-of-concept we demonstrate the use of electro-generated hydroxide ions as a lytic reagent in the preparation of cellular samples for a miniaturized total analysis system. This is a chemical method that requires no fluid inputs because reagents are generated electrochemically on-chip. Additionally, no removal of the lytic agent, hydroxide, is required since excess OH- recombines with H+ generated on-chip downstream.

A parallel-type device for high flow lysis of cells using electrochemically generated hydroxide. The inset shows a section of the device filled with red blood cells, next to the filter, which holds cells until the lysis event.

References:

Dino Di Carlo, Cristian Ionescu-Zanetti, Yolanda Zhang, Paul Hung and Luke P. Lee, "On-Chip Cell Lysis by Local Hydroxide Generation," Lab on a Chip 5 (1) (2005) (selected as hot article).