This study considers the use of a two stream microfluidic device for extraction of dimethyl sulfoxide (DMSO) from a cryopreserved cell suspension. The DMSO diffuses from a cell suspension stream into a neighboring wash stream flowing in parallel. The model of Fleming et al. [K.K. Fleming, E.K. Longmire, A. Hubel, Numerical characterization of diffusion-based extraction in a cell-laden flow through a microfluidic channel, Journal of Biomechanical Engineering 129 (2007) 703-711] is employed to determine and discuss optimal geometry and operating conditions for a case requiring removal of 95% DMSO from suspension streams with volumetric flow rates up to 2.5 ml/min. The effects of Peclet number, flow rate fraction, and cell volume fraction are analyzed, and expansion of the analysis to other applications is discussed. (C) 2008 Elsevier Ltd. All rights reserved.