All hemoglobin (Hb) types have a variable net negative charge which may cause normal and sickle cell red blood cells (RBCs) to have different mechanical properties. Here, we present a laser trapping (LT) technique for single cell ionization of RBCs with Hb C trait. The hemoglobin quantitation, conducted using a high performance liquid chromatography (HPLC), reported both Hb A and Hb C. Single RBCs were trapped and ionized by a high intensity infrared laser. The ionization energy, the charge per cell, and their relations to the size of the cells were studied. The results indicate an increase of these quantities with increase of RBC size, which is in agreement with the observations made in BT20 cells.