Raman Microspectroscopy of Normal Erythrocytes and Plasmodium Berghei -Infected Erythrocytes

Abstract

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 haem1 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.

Raman Spectroscopy of Blood and Blood Components

“…Brémard et al used RRS to characterize hemozoin 92 and Ong et al used RRS to characterize infected RBCs. 93,94 It was mentioned above (Intracellular hemoglobin) that workers at Monash University carried out some of the earliest studies of intracellular hemoglobin 16,39,41 and that, in the years since, two members of the team, Wood and McNaughton, have gone on to do much Raman spectroscopic analysis of pathological erythrocytes. In 2003, Wood, McNaughton, and co-workers reported an enhancement of a particular hemozoin Raman band (at 1374 cm…”

Studies on erythrocytes in malaria infected blood sample with Raman optical tweezers

“…13,14 Significant differences in Raman spectra have been reported for p-RBC and np-RBC in continuous in-vitro culture. 15,16 Therefore, Raman spectroscopy may help in understanding the altered properties of RBCs in malaria patients (m-RBCs). Raman optical tweezers 17,18 are particularly appropriate for probing subtle changes in m-RBCs as acquisition of Raman spectrum from RBC optically trapped in buffer media helps avoid perturbations arising due to the immobilization of the cells on substrate.…”

Raman imaging of hemozoin within the food vacuole of Plasmodium falciparum trophozoites

“…The first group [14] to report Raman microscopic measurements of single cells demonstrated the sensitivity of the technique to heme moieties in leukocytes, including eosinophil peroxidase and myeloperoxidase [15]. Resonance Raman spectra of normal and Plasmodium berghei ‐infected mouse erythrocytes fixed in methanol were reported using 488 nm excitation [16] and more recently 633 nm excitation [17]. Our work has focussed on characterizing and interpreting the Raman spectra of single functional erythrocytes in both the oxygenated and deoxygenated state [18–20].…”