Returning to Diagnostic Basics

Figures & data

George Whitesides' group at Harvard University has developed microfluidic paper-based analytical devices (µPADs).

Photoresist was soaked in paper and then cured under UV light to create hydrophobic barriers that define the channels on individual paper layers. The paper layers were then stacked with double-sided tape to create multilayer devices (on the left and the right). The center device shows how a single liquid sample moves passively through capillary action within defined channels to four termini that can contain different reagents. In the center device, the two channels on the right contain protein assay reagents which detect bovine serum albumin (BSA) in artificial urine through a color change. The channels on the left serve as controls. Images courtesy of George M. Whitesides.

George M. Whitesides, Woodford L. and Ann A. Flowers University Professor at Harvard University.

Image courtesy of George M. Whitesides.

Smaller than a shoebox, this handheld diagnostic device by Claros Diagnostics costs about $100 and uses disposable plastic cards.

The company has developed a quick test for prostate-specific antigen and an ELISA-type assay for HIV and other sexually transmitted diseases. Image courtesy of Samuel Sia.