A Tough Nut to Crack: Intracellular Detection and Quantification of Heme in Malaria Parasites by a Genetically Encoded Protein Sensor.

How free is heme? A fluorescent sensor has been used by Niles and co-workers to detect heme in P. falciparum. ECFP and EYFP were attached to its termini to give a FRET signal that was quenched by heme binding. The sensor was used to investigate alterations in the labile heme pool during the parasite's life cycle as well as under the influence of the drug chloroquine.