Infrared Light Detects and Quantifies Malaria Parasites

The quick and inexpensive test uses infrared light to detect malaria at a very early stage of its development by looking for fatty acids in the parasite and could dramatically reduce the number of people who die from the disease.

Scientists at Monash University (Clayton, VIC, Australia) maintained cultured Plasmodium falciparum parasites synchronized to ring stages by sorbitol lysis. High parasitemia ring-stage cultures were obtained by seeding uninfected red blood cells with purified schizont-stage parasites that were allowed to reinvade under shaking conditions overnight, reducing multiple infections.

The method to rapidly detect and quantify different stages of malaria parasites, including ring and gametocyte forms, used attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) and partial least-squares regression (PLS). A Bruker model Equinox 55 (Bruker Optic; Ettingen, Germany) FT-IR spectrometer fitted with a nitrogen-cooled mercury–cadmium–telluride (MCT) detector and a golden gate diamond ATR accessory (Specac Limited; Orpington, UK) was used for spectral acquisition. ATR-FTIR utilizes infrared light to detect the vibrations of molecules and essentially depicts the entire chemistry of the system under investigation.

The scientists already knew that fatty acids were a marker for the disease from previous studies at the Australian Synchrotron. The Synchrotron allowed the team to see the different life stages of the parasite and the variation in its fatty acids. They then applied these insights to develop an inexpensive laboratory based test that has the potential to be portable. The results confirmed the ability of ATR-FT-IR to detect parasitaemia levels down to 0.00001%.

Bayden R. Wood, PhD, the senior author of the study, said, “Not only did the test give clear results within minutes, it gave a clear indication of malaria at a much earlier stage of infection than current tests on the market. Now that we can detect the early stages of a parasite's life in the blood stream the disease will be much easier to test and treat. The big advantage of our test is that it doesn't need scientists and expensive equipment. This has the potential to dramatically reduce the number of people dying from this disease in remote communities.” The study was published on April 2, 2014, in the journal Analytical Chemistry.

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Monash University
Bruker Optic
Specac Limited