Raman spectroscopy was applied to study β-haematin, normal erythrocytes, parasite-infected erythrocytes, and lysed samples of the parasite-infected erythrocytes. Differences were observed between spectra excited by the Ar+ laser and those excited by the HeNe laser. The significant difference lies in the fact that with the HeNe laser excitation at 632.8 nm, band absorption is a result of the charge transfer, while laser excitation in Qv-absorption bands of the active site of the haem occurs for the Ar+ laser. Similarity in the spectra of β-haematin and parasite-infected erythrocyte was observed with the HeNe laser. The differences between the normal erythrocyte and the parasite-infected erythrocyte may still be distinguished by the band at 754 cm-1 for the parasite-infected erythrocyte. In addition, with the HeNe laser, the band at 1080 cm-1 may also be used as a reference to whether the erythrocyte has been infected.
C. W. Ong, Z. X. Shen, K. K. H. Ang, U. A. K. Kara, and S. H. Tang, "Raman Microspectroscopy of Normal Erythrocytes and Plasmodium berghei-Infected Erythrocytes," Appl. Spectrosc. 56, 1126-1131 (2002)