Human red blood cells, in which membrane proteins are targeted and labeled with quantum dots, reveal the clustering behavior of the proteins. The number of purple features, which indicate the nuclei of malaria parasites, increases as malaria development progresses. The NIST logo at bottom was made by a photo lithography technique on a thin film of quantum dots, taking advantage of the property that clustered dots exhibit increased photoluminescence. A quantum dot (QD) is a nanocrystal made of semiconductor materials that is small enough to exhibit quantum mechanical properties. Malaria is a mosquito-borne infectious disease of humans and other animals caused by parasitic protozoans belonging to the genus Plasmodium.