Unlike traditional antibody-based fluorescent staining methods, the new dye directly binds to the cell membranes of the target cells.
Human blood contains several different components, including plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets. Among these, WBCs are divided into numerous subcategories each with unique functions and characteristics, such as lymphocytes, monocytes, neutrophils, and others. Lymphocytes are further subdivided into T lymphocytes, B lymphocytes, and Natural Kller cells. Distinguishing and separating different types of these cells is highly important in carrying out studies in the field of immunology.
Discriminating different immune cell types is typically done by flow cytometry and fluorescence-activated cell sorting (FACS), which can identify distinct populations of cells according to their size, granularity, and fluorescence. While size and granularity alone cannot distinguish cells with similar physical parameters, different types of immune cells display a distinct combination of immune receptors on the cell surfaces. For example, the T lymphocytes and B lymphocytes express CD3 and CD19, respectively. Therefore, fluorescently identifying immune cells have relied on staining the cells using multiple antibodies against different receptors. It has been long thought that it was impossible to distinguish different immune cell types without using these antibodies.
