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red blood cell; Credit: St Jude
Children’s Research Hospital
Researchers have found they can diagnose malaria using magnetic fields to detect a byproduct of malarial metabolism.
They used magnetic resonance relaxometry (MRR) to detect a parasitic waste product called hemozoin in malaria-infected red blood cells from mice and humans.
The team said MRR is more sensitive than other methods of detecting malaria, can be carried out using a portable benchtop system, and costs less than 10 cents per test.
Jongyoon Han, PhD, of the Massachusetts Institute of Technology in Cambridge, and his colleagues described the technique in Nature Medicine.
When malaria parasites infect red blood cells, they feed on the nutrient-rich hemoglobin. As hemoglobin breaks down, it releases iron, which can be toxic, so the parasite converts the iron into hemozoin—a weakly paramagnetic crystallite.
Those crystals interfere with the normal magnetic spins of hydrogen atoms. When exposed to a powerful magnetic field, hydrogen atoms align their spins in the same direction.
When a second, smaller field perturbs the atoms, they should all change their spins in synchrony. But if another magnetic particle, such as hemozoin, is present, this synchrony is disrupted through a process called relaxation. The more magnetic particles present, the more quickly the synchrony is disrupted.
“What we are trying to really measure is how the hydrogen’s nuclear magnetic resonance is affected by the proximity of other magnetic particles,” Dr Han said.
This MRR technique enables malaria diagnosis because hemozoin crystals are produced in all 4 stages of malaria infection and are generated by all known species of the Plasmodium parasite. Furthermore, the amount of hemozoin can reveal how severe the infection is, or whether it is responding to treatment.
Dr Han and his colleagues found they could use MRR to detect Plasmodium falciparum infection to as low as 0.0002% parasitemia in 750 nl of cultured blood in less than 5 minutes.
They also detected Plasmodium berghei in mice, allowing for reliable estimation of parasitemia to as low as 0.0001%.
The device the researchers used in this study is small enough to sit on a table or lab bench, but they are working on a portable version the size of a small electronic tablet.
“This system can be built at a very low cost, relative to the million-dollar MRI machines used in a hospital,” said study author Weng Kung Peng, PhD, of the Singapore-MIT Alliance for Research and Technology Centre in Singapore.
“Furthermore, since this technique does not rely on expensive labeling with chemical reagents, we are able to get each diagnostic test done at a cost of less than 10 cents.”
The researchers are launching a company to make this technology available at an affordable price. The team is also running field tests in Southeast Asia and exploring powering the device on solar energy. 
red blood cell; Credit: St Jude
Children’s Research Hospital
Researchers have found they can diagnose malaria using magnetic fields to detect a byproduct of malarial metabolism.
They used magnetic resonance relaxometry (MRR) to detect a parasitic waste product called hemozoin in malaria-infected red blood cells from mice and humans.
The team said MRR is more sensitive than other methods of detecting malaria, can be carried out using a portable benchtop system, and costs less than 10 cents per test.
Jongyoon Han, PhD, of the Massachusetts Institute of Technology in Cambridge, and his colleagues described the technique in Nature Medicine.
When malaria parasites infect red blood cells, they feed on the nutrient-rich hemoglobin. As hemoglobin breaks down, it releases iron, which can be toxic, so the parasite converts the iron into hemozoin—a weakly paramagnetic crystallite.
Those crystals interfere with the normal magnetic spins of hydrogen atoms. When exposed to a powerful magnetic field, hydrogen atoms align their spins in the same direction.
When a second, smaller field perturbs the atoms, they should all change their spins in synchrony. But if another magnetic particle, such as hemozoin, is present, this synchrony is disrupted through a process called relaxation. The more magnetic particles present, the more quickly the synchrony is disrupted.
“What we are trying to really measure is how the hydrogen’s nuclear magnetic resonance is affected by the proximity of other magnetic particles,” Dr Han said.
This MRR technique enables malaria diagnosis because hemozoin crystals are produced in all 4 stages of malaria infection and are generated by all known species of the Plasmodium parasite. Furthermore, the amount of hemozoin can reveal how severe the infection is, or whether it is responding to treatment.
Dr Han and his colleagues found they could use MRR to detect Plasmodium falciparum infection to as low as 0.0002% parasitemia in 750 nl of cultured blood in less than 5 minutes.
They also detected Plasmodium berghei in mice, allowing for reliable estimation of parasitemia to as low as 0.0001%.
The device the researchers used in this study is small enough to sit on a table or lab bench, but they are working on a portable version the size of a small electronic tablet.
“This system can be built at a very low cost, relative to the million-dollar MRI machines used in a hospital,” said study author Weng Kung Peng, PhD, of the Singapore-MIT Alliance for Research and Technology Centre in Singapore.
“Furthermore, since this technique does not rely on expensive labeling with chemical reagents, we are able to get each diagnostic test done at a cost of less than 10 cents.”
The researchers are launching a company to make this technology available at an affordable price. The team is also running field tests in Southeast Asia and exploring powering the device on solar energy.
red blood cell; Credit: St Jude
Children’s Research Hospital
Researchers have found they can diagnose malaria using magnetic fields to detect a byproduct of malarial metabolism.
They used magnetic resonance relaxometry (MRR) to detect a parasitic waste product called hemozoin in malaria-infected red blood cells from mice and humans.
The team said MRR is more sensitive than other methods of detecting malaria, can be carried out using a portable benchtop system, and costs less than 10 cents per test.
Jongyoon Han, PhD, of the Massachusetts Institute of Technology in Cambridge, and his colleagues described the technique in Nature Medicine.
When malaria parasites infect red blood cells, they feed on the nutrient-rich hemoglobin. As hemoglobin breaks down, it releases iron, which can be toxic, so the parasite converts the iron into hemozoin—a weakly paramagnetic crystallite.
Those crystals interfere with the normal magnetic spins of hydrogen atoms. When exposed to a powerful magnetic field, hydrogen atoms align their spins in the same direction.
When a second, smaller field perturbs the atoms, they should all change their spins in synchrony. But if another magnetic particle, such as hemozoin, is present, this synchrony is disrupted through a process called relaxation. The more magnetic particles present, the more quickly the synchrony is disrupted.
“What we are trying to really measure is how the hydrogen’s nuclear magnetic resonance is affected by the proximity of other magnetic particles,” Dr Han said.
This MRR technique enables malaria diagnosis because hemozoin crystals are produced in all 4 stages of malaria infection and are generated by all known species of the Plasmodium parasite. Furthermore, the amount of hemozoin can reveal how severe the infection is, or whether it is responding to treatment.
Dr Han and his colleagues found they could use MRR to detect Plasmodium falciparum infection to as low as 0.0002% parasitemia in 750 nl of cultured blood in less than 5 minutes.
They also detected Plasmodium berghei in mice, allowing for reliable estimation of parasitemia to as low as 0.0001%.
The device the researchers used in this study is small enough to sit on a table or lab bench, but they are working on a portable version the size of a small electronic tablet.
“This system can be built at a very low cost, relative to the million-dollar MRI machines used in a hospital,” said study author Weng Kung Peng, PhD, of the Singapore-MIT Alliance for Research and Technology Centre in Singapore.
“Furthermore, since this technique does not rely on expensive labeling with chemical reagents, we are able to get each diagnostic test done at a cost of less than 10 cents.”
The researchers are launching a company to make this technology available at an affordable price. The team is also running field tests in Southeast Asia and exploring powering the device on solar energy.