What is the Difference Between Flow Cytometry and Immunohistochemistry?

Flow cytometry and immunohistochemistry are both laboratory techniques used to detect antigens on cell surfaces or within cells. However, they have some key differences:

1. Technique: Flow cytometry is a laser-based technique that uses a flow cytometer for detecting and quantifying physical and chemical properties of cells. Immunohistochemistry, on the other hand, is a microscopy-based technique that uses monoclonal or polyclonal antibodies for selective identification of proteins or other molecules in cells.
2. Instrumentation: Flow cytometry requires a flow cytometer, while immunohistochemistry needs a light or fluorescent microscope.
3. Antigen Detection: Flow cytometry uses a laser beam for detecting antigens, whereas immunohistochemistry relies on monoclonal or polyclonal antibodies.
4. Simultaneous Marker Assessment: Flow cytometry can assess multiple markers (up to 10) simultaneously, while immunohistochemistry is generally limited to assessing one or two markers at a time.
5. Sensitivity: Flow cytometry can detect weakly expressed antigens, whereas immunohistochemistry may not be as sensitive.
6. Cost: Immunohistochemistry has relatively lower costs compared to flow cytometry.

While both techniques have their advantages and limitations, they are considered complementary in some cases, and flow cytometry is often superior to immunohistochemistry for detecting certain antigens or epitopes present in cells.

Comparative Table: Flow Cytometry vs Immunohistochemistry

Flow cytometry and immunohistochemistry (IHC) are both techniques used to analyze and detect specific proteins expressed by cells. However, they have some differences in terms of their applications, sensitivity, and the type of information they provide. Here is a table highlighting the differences between flow cytometry and immunohistochemistry:

In summary, flow cytometry is typically used for analyzing cells in suspension and measuring various physical properties of cells, while immunohistochemistry is used for evaluating protein expression and tissue architecture in cells within tissue sections. Flow cytometry is generally faster and less expensive than immunohistochemistry, but IHC can provide additional information on tissue architecture and patterns of involvement.