Researchers at MIT have found a way to detect early-stage malarial infection of blood cells by measuring changes in the infected cells' electrical properties.
The scientists have built an experimental microfluidic device that takes a drop of blood and streams it across an electrode that measures a signal differentiating infected cells from uninfected cells.
The ultimate goal would be to create a postage stamp-sized device with integrated electronics that can detect if a person has malaria and at what stage. Similar diagnostics may be applicable to other infections and diseases.
The cell-counting microfluidic device is similar to other low-cost, portable devices being developed to diagnose illnesses such as HIV.
The researchers optimized the electronics to allow very accurate measurements of impedance for each cell as it passes by. The researchers had to minimize interfering electric signals from the substrate the blood flows over and prevent the cells from sticking to one another.
In tests of cells of four cell types the device detected small differences in measurements of magnitude and seemingly random differences in phase, but not quite enough to definitively differentiate among the three stages of an infected cell.
By mathematically combining the measures into an index called delta, the differences between uninfected cells and all three stages became clear.
The MIT team of experts spans a number of disciplines including microfluidics, circuit design, materials science and microbiology. They have designed the new cell-differentiating technology so it can be packaged as a low-cost device
For more information, see the paper "Electric impedance microflow cytometry for characterization of cell disease states" was published in this month’s issue of the journal Lab on a Chip.
