Monitoring the Uptake of Glycosphingolipids In Plasmodium falciparum-Infected Erythrocytes Using Both Fluorescence Microscopy and Capillary Electrophoresis with Laser-Induced Fluorescence Detection

The metabolism of glycosphingolipids by the malaria-causing parasite Plasmodium falciparum plays an important role in the progression of the disease We report a new and highly sensitive method to monitor the uptake of glycosphingolipids in infected red blood cells (iRBCs) A tetramethylrhodamine-labeled glycosphingolipid (GM1 TMR) was used as a substrate Uptake was demonstrated by fluorescence microscopy The IRBCs were lysed with a 15% solution of saponin and washed with phosphate buffered saline to release intact parasites The parasites were further lysed and the resulting homogenates were analyzed by capillary electrophoresis with laser-induced fluorescence detection The lysate from erythrocytes infected at 1% parasitemia generated a signal 20 standard deviations larger than uninfected erythrocytes, which suggests that relatively low infection levels can be studied with this technique