Laser trap ionization for identification of human erythrocytes with variable hemoglobin quantitation

Abstract

An approach to an established technique that is potentially applicable for a more comprehensive understanding of the electrical properties of red blood cells (RBCs) is presented. Using a high-intensity gradient laser trap, RBCs can be singly trapped and consequentially ionized. The subsequent dynamics of the ionized cell allows one to calculate the charge developed and the ionization energy (IE) through a Newtonian-based analysis. RBCs with two different hemoglobin (Hb) types were ionized. The first sample was identified as carrying Hb HbAA (normal Hb) and the second one was identified as carrying HbAC (HbC trait). By analyzing the charge developed on each cell and several other related factors, we were able to discern a difference between the main Hb types contained within the individual RBC, independent of cell size. A relationship between the charge developed and the IE of the cell was also established based on the electrical properties of RBCs. Thus, we present this laser trapping technique as a study of the electrical properties of RBCs and as possible biomedical tool to be used for the differentiation of Hb types.

Chemo-treated 4T1 breast cancer cells radiation response measured by single and multiple cell ionization using infrared laser trap

“…This study uses a new approach that uses laser trapping technique (LT) 17 for single cell ionization. We have recently demonstrated this approach in BT20 breast cancer cells 18 and human red blood cells 19,20 . This study uses a high-power infrared laser (at 1064 nm) to measure the radio sensitivity of 4T1 breast carcinoma cell lines treated by a naturally occurring compound, 2-Dodecyl-6-methoxycyclohexa-2, 5-diene-1, 4-dione (DMDD) extracted from the root of Averrhoa carambola L. Studies have shown that DMDD induces apoptosis of various human breast cancer cells through production of intracellular reactive oxygen species (ROS) and inhibition of NF-κB activation 21 .…”

Optical Tweezers in Studies of Red Blood Cells

“…Other potential nonthermal cell damages caused by linear optical excitation, nonlinear photonic effects and reactive oxygen species/singlet oxygen as a consequence of high-intensity near-infrared laser radiation need to be considered when trapping biological objects [16,87]. In optical trapping of human RBCs, except for the undesirable temperature rise, studies have revealed the OTs-induced deoxygenation of the trapping site on the RBC surface that is proportional to the trapping power [88] and have observed cell membrane ionization, inactivation and ejection from the trap by the thermally produced (radiometric) force induced by high power infrared laser trapping [89][90][91]. The observed RBC membrane rupture under high laser power (>500 mW) has been proven to be caused by the membrane electro-permeabilization and the resulting strong temperature gradient across the cell membrane induced by shape changes, rather than the total temperature rise (1.4 • C/100 mW) around the cell [89].…”

“…With conventional OTs-based methods, diagnostic and therapeutic models of certain diseases, including sickle cell disorders, have been established based on the direct evaluation of RBC mechanical and physical properties [90,[122][123][124]. The efficacy of blood transfusion treatment in sickle cell anemia (SCA) has been evaluated by analyzing the mechanical response of transfused RBCs measured by conventional OTs [124].…”

“…With the terminal moving velocity measurement method, a decrease of 42% in RBC zeta potential after 15-day storage was observed [138]. In particular, some studies have reported the phenomenon of RBC ejection from an optical trap as a mutual result of trapping force, viscous friction force that is applied by the suspending medium and the laser-induced electrostatic force due to membrane ionization under high infrared (1064 nm) trapping power [90,91]. According to the RBC ionization energy, the time required for ionization and the number of charges formed on the cell surface measured with OTs, RBCs containing two different types of hemoglobin are differentiated as a result of the fact that different kinds of hemoglobin carry a different amount of charges [90].…”

“…In particular, some studies have reported the phenomenon of RBC ejection from an optical trap as a mutual result of trapping force, viscous friction force that is applied by the suspending medium and the laser-induced electrostatic force due to membrane ionization under high infrared (1064 nm) trapping power [90,91]. According to the RBC ionization energy, the time required for ionization and the number of charges formed on the cell surface measured with OTs, RBCs containing two different types of hemoglobin are differentiated as a result of the fact that different kinds of hemoglobin carry a different amount of charges [90]. The obtained results have enabled a better understanding of the relation between the cell charge and the electrolytic environment, and the proposed methodology with OTs provides an effective tool for comprehensive studies of the electrical properties of both RBCs and other types of biological samples.…”