Background: Malaria remains the first global parasitic endemic disease with more than 400,000 deaths per year;
there is a definite need for prevention measures and treatments, but also for rapid and low-cost diagnostic methods. Hemozoin, a detoxification polymer formed from heme by the parasite, and a likely biomarker of infection, has enticed many studies aiming at its whole blood determination. But, to our best knowledge, no accurate, precise and sensitive analytical method has been developed that could be implemented in endemic regions.
Objectives: Our group recently proposed a macroscopic trapping-dissolution method based on the paramagnetic
properties of hemozoin crystals. The present paper further develops the concept into a workable fluidic device,
validating an instrumental method that could be applied to the diagnosis of malaria.
Results: In the newly developed integrated on-line system, the paramagnetic crystals are successively trapped through a superparamagnetic microbeads gradient field, dissolved by an alkaline solution, losing magnetic
properties, eluted and quantified by spectrophotometry at 405 nm. The analysis time is comprised between 10
and 15 min. The performances of the method have been evaluated both on aqueous suspensions of β-hematin (a
synthetic pigment with physical and paramagnetic properties analogous to those of hemozoin) and Plasmodium
cultures, including the response function, linearity, precision, trueness, accuracy and quantification limits. From
β-hematin suspensions and Plasmodium falciparum 3D7 cultures, the limit of detection would correspond to 80
and 55 parasites/µL whole blood, respectively (0.05 and 0.033 µg hemozoin/mL).
Conclusion: In the absence of a reference method for the determination of hemozoin, its value as a malaria
biomarker remains a matter of heavy debates. The newly developed magneto-chromatographic on-line system
can discriminate the presence and absence of hemozoin in a sample but also accurately and precisely determine
its level; application to whole-blood samples from strictly graded patients will allow to precise the usefulness of
hemozoin for malaria diagnosis and/or prognosis.

Malaria, Hemozoin, Paramagnetism, Diagnostic, Magnetic Chromatography