Spatially modulated fluorescence emission from moving particles
A fundamentally new design for the optical detection system in a flow cytometer is described that delivers high effective sensitivity (i.e., high signal-to-noise discrimination) without complex optics or bulky, expensive light sources to enable a flow cytometer that can combine high performance, robustness, compactness, low cost, and ease of use. The enabling technique is termed "spatially modulated emission" and involves relative movement between a fluorescing bio-particle and a selectively patterned environment to produce a time-modulated signal that is analyzed with real-time correlation techniques. The advantages are high discrimination of the particle signal from background noise and elimination of sophisticated optics and critical optical alignment. The technique is demonstrated with measurements of fluorescent beads flowing through a fluidic chip.
Kiesel, P. ; Bassler, M. ; Beck, M. ; Johnson, N. M. Spatially modulated fluorescence emission from moving particles. Applied Physics Letters. 2009 January 26; 94 (4): 041107.