In the context of flow cytometry, what does permeabilization facilitate?

Permeabilization is a crucial step in flow cytometry that allows antibodies and other reagents to access the interior of cells. This process involves the disruption of the cell membrane, enabling larger molecules, such as intracellular proteins and antigens, to enter the cells and bind to specific antibodies. Intracellular staining is essential for studying the expression of proteins that are located within the cell, as it provides insights into the functional state of cells, signaling pathways, and various cellular processes.

In contrast, options that relate to blocking non-specific binding, cell fixation, or cell collection do not pertain directly to the role of permeabilization. Blocking of non-specific binding typically happens before permeabilization to ensure that antibodies bind specifically to their target. Cell fixation serves to stabilize the cellular structure, often done before permeabilization. Cell collection refers to the gathering of cells for analysis but does not involve the mechanism of permeabilizing cells to allow for intracellular examination. Thus, intracellular staining is the correct context for understanding the function of permeabilization in flow cytometry.