The different types of ribonucleic acid (RNA) tests are human immunodeficiency virus (HIV) RNA tests, Hepatitis C tests, and gene tests. HIV RNA tests are called polymerase chain reaction (PCR) tests and they look for the RNA of the virus or the presence of HIV DNA in white blood cells. Hepatitis C RNA tests are qualitative RNA tests and quantitative RNA tests. Gene tests look at the RNA in genes taken from a blood sample to detect the presence or possibility of a disease or disorder.
HIV RNA tests often are used on newborn babies to detect HIV infection in infants whose mothers are HIV-positive. The virus's RNA is detected via a PCR, which analyzes short sequences of RNA. It reproduces sections of cellular RNA in test tubes, with an enzyme called polymerase that creates a copy of the RNA segment. Once the polymerase is finished copying the RNA, it can be studied to detect the presence of HIV RNA. These tests also are called viral load tests and HIV nucleic acid amplification testing (NAAT).
Hepatitis C qualitative RNA tests are used to determine if the virus is present in the body. Quantitative Hepatitis C RNA tests, or viral load tests, are used to estimate the level of Hepatitis C RNA in the blood. One test confirms whether a person is infected with the Hepatitis C virus, and the other gives the doctor an idea of how much of the virus is in the body. Hepatitis C attacks the liver and can cause cirrhosis. Knowing if a person is infected with the virus helps in starting treatment and taking the proper precautions to prevent the spread of the disease.
Gene RNA tests are used to examine strands of RNA for changes in the genes or DNA strand of a cell. These changes include missing sections, extra sections or altered chemical bases or sub-units within a DNA strand. The tests often are used to determine if a person is a carrier for a genetic disease that can be passed on to his or her children and if an unborn baby has a genetic disorder. Diseases that can be diagnosed with a gene RNA test include birth defects, chromosomal abnormalities, Tay-Sachs disease, Down syndrome and spina bifida.
There are three types of RNA: messenger RNA (mRNA), transfer RNA (tRNA) and ribosomal RNA (rRNA). Messenger RNA takes information from deoxyribonucleic acid (DNA) or genetic information in a cell to the ribosome of the cell to make protein. At this point, tRNA takes amino acids to the mRNA in the cell's ribosome to put the protein together. The structural component of the cell's ribosome, rRNA is where it synthesizes proteins.