Using a single drop of blood, a team of engineers at the University of Wisconsin-Madison has developed what they say is a faster, cheaper, and more accurate tool for diagnosing even mild cases of asthma.

The handheld technology, which uses a previously unknown correlation between asthmatic patients and the most abundant type of white blood cells in the body, neutrophils, means doctors could diagnose asthma even if their patients are not experiencing symptoms during their visit to the clinic.The team said that this is one of the first studies to show that this process could actually work in a cheap, easy and practical way.

Asthma is difficult to accurately diagnose. Currently, diagnosis consists of a series of lung functionality tests. But, many of the tests rely, at least partially, on the patient experiencing symptoms during or close to their physician visit.

To directly diagnose asthma, they tracked the velocity at which the neutrophil cells migrate to differentiate non-asthmatic samples from the significantly reduced chemotaxis velocity of asthmatic patients.

Traditionally, a clinical study of neutrophils required so much blood work, specialized equipment, and processing that it was impractical to use in diagnostics. However, UW-Madison students developed a kit-on-a-lid-assay (KOALA) microfluidic technology, which allowed them to detect neutrophils using just a single drop of blood.

The KOALA diagnostic procedure uses simple plastic lids and bases. Diagnosticians place a KOALA lid containing a chemical mixture onto the base containing the blood sample. That chemical mixture triggers neutrophil migration so the researchers can automatically track and analyze the neutrophil chemotaxis velocity using custom software.

By using the lids containing pre-mixed chemicals, the diagnostic procedure is scalable, cheap, quick and repeatable.

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