A paper microfluidic cartridge for automated staining of malaria parasites with an optically transparent microscopy window

• Published in: Lab on a chip Vol. 14; no. 12; p. 2040
• Main Authors: Horning, Matthew P, Delahunt, Charles B, Singh, S Ryan, Garing, Spencer H, Nichols, Kevin P
• Format: Journal Article
• Language: English
• Published: England 21-06-2014
• Subjects: Acridine Orange - chemistry; Humans; Malaria, Falciparum - blood; Plasmodium falciparum - cytology; Staining and Labeling - instrumentation; Staining and Labeling - methods
• ISSN: 1473-0189
• DOI: 10.1039/c4lc00293h

A paper microfluidic cartridge for the automated staining of malaria parasites (Plasmodium) with acridine orange prior to microscopy is presented. The cartridge enables simultaneous, sub-minute generation of both thin and thick smears of acridine orange stained parasites. Parasites are stained in a cellulose matrix, after which the parasites are ejected via capillary forces into an optically transparent chamber. The unique slanted design of the chamber ensures that a high percentage of the stained blood will be of the required thickness for a thin smear, without resorting to spacers or other methods that can increase production cost or require tight quality controls. A hydrophobic snorkel facilitates the removal of air bubbles during filling. The cartridge contains both a thin smear region, where a single layer of cells is presented unobstructed, for ease of species identification, and a thick smear region, containing multiple cell layers, for enhanced limit of detection.