Fig. 4

Absorbance spectra of Hz haem for the ring (gray) and trophozoite (black) stages obtained from the same culture. The Soret peak obtained from the ring stage is very weak compared to that from the trophozoite stage. The maximum content of haemozoin in the ring culture is 4.2 ± 0.4 % (n = 4) of that in the trophozoites. In order to detect a significant signal from the ring stage, these experiments were conducted with 2.5 × 10⁷ parasites