Deoxyribonucleic acid (DNA) can be measured in cell samples by using DNA flow cytometry. The procedure generally involves the use of a biological sample, the cells of which are marked with fluorescent substances and passed through a laser beam. Computers can then determine the types of cells, including helper, suppressor, or killer immune cells that are present, for example. The process is usually quick, so hundreds of samples can be analyzed each day and many types of cells are often analyzed as well. It typically helps to characterize DNA content, which is called ploidy, in a sample, and can be used in scientific studies of plants or for detecting blood cancers and predicting patient prognosis.
The results of DNA flow cytometry are often displayed on a chart called a bar-graph historgram. Peaks in the lines typically represent how concentrated certain cells are. Comparisons of one cell type to another can be made by viewing the height of each peak on the graph. The state of DNA in animals and plants can often be determined as well. Cell cycles are often analyzed for either; samples ready to multiply generally have DNA that is in a different state than cells in between dividing cycles.
If an unusual number of cells are in a dividing stage, then DNA flow cytometry can help diagnose certain types of cancer. Analysts are often able to determine whether a tumor is growing, how aggressive it is, and what the prognosis of a condition may be. Flow cytometry can be useful for testing bone marrow for lymphoma or leukemia, immune cells for the progression of Human Immunodeficiency Virus (HIV), or cell samples for detecting gastric, ovarian, or prostate cancers.
Composition of genetic material can be determined by DNA flow cytometry as well. Base pairs of nucleotides in DNA can be detected and their total composition estimated. Samples are sometimes measured after a dose of radiation to measure the effects on cellular genetics. The chromosomes of different plant types and their variants can also be analyzed. In addition to finding diseases, DNA flow cytometry is often used to track cell groups.
The use of DNA flow cytometry alone for making a medical prognosis is sometimes disputed. Similar results are occasionally seen in either malignant or benign tumors that are tested. Many laboratory researchers continue to improve the process in the early 21st century, and use it to study the state of DNA in relation to cell activity.
