Uses of Clinical Flow Cytometry

Flow cytometry is a technology that measures the characteristics of microscopic particles such as cells and chromosomes, by looking at how they flow in a stream of liquid. Flow cytometry is used for diagnosis of diseases such as blood cancer but also has many applications in clinical practice. This technique has been used for the identification of microbial cells and for the analysis of antimicrobial drug-cell interactions. Some of the common clinical uses are in leukemia characterization, immune studies such as T and B cell subset determinations, stem cell content monitoring for transplant, nuclear ploidy and cell cycle determinations.

DNA Content

• A cell's DNA content can be measured using this technique. Flow cytometry allows analyzing the cell cycle and helps to identify the cell distribution during the various phases of the cell cycle. A fluorescent dye that binds to the DNA is added to a suspension of single cells or nuclei. The stained DNA is then measured by a flow cytometer, which emits fluorescent signals. These signals give an electronic pulse, which is the measure of the cellular DNA content.

  The analysis of the DNA content is a useful indicator, especially in defining patient prognosis beyond the classic pathologic staging. DNA analysis is also useful for patients with colorectal tumors. The DNA content identified by flow cytometry was used for prognosis of node-positive breast cancer.

Evaluation of Cell-Surface Markers

• Flow cytometry can be used to determine the types of receptors and makers on the cell surface. For evaluation of the cell surface, a fluorescent dye is attached to antibodies, which then use a flow cytometer that determines the amount of receptors on the cell surface by measuring the level of fluorescence.

  The evaluation of the cell surface markers helps in diagnosis of acute and chronic rejection of the renal allograft. It is also used as tool in the assessment of lung cancer.

Cell Sorting

• One of the primary applications of flow cytometry is to analyze the cell cycle. During the analysis of a cell cycle, flow cytometer can be used to sort a subset of cells within the whole population.

  Cell sorting helps in identifying cells of higher purity. It helps to separate the cells based on their fluorescence intensity and based on multiple antibodies. Cell sorting also enables to eliminate dead cells.