Laboratory Testing : Medical Assistants Class



  • A blood or urine test that detects the levels of hCG in the body is a:

    pregnancy test

    Rationale: hCG is human chorionic gonadotropin (hCG), which is a hormone that is produced by the placenta during pregnancy. This hormone can be detected by a urine or blood test within a few weeks after conception. Both tests are fairly accurate, as long as enough time has passed to assure that the hormones are present in the body.

  • A blood test that can determine the type of microorganism that may be present in the blood is a:

    blood culture

    Rationale: Blood cultures are used to detect the presence of bacteria or yeasts in the blood, to identify any microorganisms present, and to guide treatment for medical conditions. Two or more blood cultures are typically ordered and collected as consecutive samples. Often, a complete blood count is usually ordered along with the blood culture to determine whether the person has an increased number of white blood cells, which could indicate a potential infection. Blood cultures may be ordered when a person is having symptoms of sepsis, such as fever, nausea, decreased urine output, or increased heart rate. If blood cultures are positive, it most likely means that a person has a bacterial or yeast bloodstream infection that needs to be treated immediately. If the blood culture sets are both negative, the probability that a person has sepsis caused by bacteria or yeasts is low.

  • A blood test that gives an overall picture of the body's metabolism is a:

    blood chemistry

    Rationale: Metabolism refers to all the physical and chemical processes in the body that use energy. To measure the metabolism, a blood chemistry test is order. There are numerous names for the test, such as chem-7, chem-10 and basic metabolic panel. The information in a blood chemistry can indicate how the kidneys and liver are working, as well as levels of electrolytes and the levels of other blood components. The electrolytes commonly measured on a blood chemistry are sodium, potassium, and chloride. Other levels that are measured are blood sugar, cholesterol, calcium, and protein.

  • A laboratory test that checks different components of the urine is a:


    Rationale: The urine is made up of hundreds of waste materials, minerals, fluids, and other substances from the blood that has passed through the kidneys. More than 100 different tests can be done on urine, and the most common is a regular urinalysis. A urinalysis contains information about a urine specimen, including physical appearance and chemical components. Physically, the color, clarity, and odor of the urine is described. A urinalysis also contains the specific gravity, which checks the amount of substances in the urine. A urinalysis test will also indicate the presence of materials that should not be in the urine, or should not be found in large amounts. For example, protein, glucose, nitrate, leukocytes, and ketones should not normally be present in the urine, but are indicated on a urinalysis if found. If a urinalysis is abnormal, further testing may be indicated to determine what is going on with a patient.

  • A quick screening test that can detect a recent mononucleosis infection is a :

    monospot test

    Rationale: A monospot test is a quick screening test that can detect a type of antibody known as the heterophil antibody. The heterophil antibody forms during certain infections. To perform a monospot test, a sample of blood is placed on a microscope slide and mixed with other substances. If heterophil antibodies are present, the blood clumps together, which usually indicates a mono infection. Monospot testing can usually detect antibodies 2 to 9 weeks after a person is infected. It typically is not used to diagnose mono that started more than 6 months earlier.

  • A test that looks for hidden blood in the stool is:

    guaiac test

    Rationale: The stool guaiac test looks for hidden blood in a stool sample. It can find blood even if it cannot be seen with the naked eye. It is the most common type of fecal occult blood test. To perform the test, a small amount of stool is obtained, usually during a bowel movement or rectal exam. The sample is placed on a hemoccult card, and a testing solution is applied to the card. If the card turns blue, then blood is present in the specimen. A positive result would be an indicator to do more diagnostic testing, and find the source of the bleeding.

  • A test that screens a person for exposure to tuberculosis is a:

    TB skin test

    Rationale: TB screening tests are used to screen certain people who are at high risk for TB exposure, or as part of a routine examination prior to starting a new job or school. The test is performed by placing a small amount of TB units under the surface of the skin. After two days, the skin is evaluated to see if there is a reaction to the TB. A positive reaction is when the skin is raised at the site of injection. If a patient has a positive PPD skin test, then a chest x-ray is required to assess the lungs for presence of the TB infection in the lungs. People that are at the highest risk for exposure to TB are those with diseases or conditions that weaken the immune system, such as those with HIV or AIDS. Also, those who are in confined living conditions such as homeless shelters, nursing homes, schools, and correctional facilities. TB skin testing is a required for medical personnel that will provide care to patients, or work in a medical facility.

  • A throat swab that is done to determine if a sore throat is caused by a certain bacteria or a virus is:

    rapid strep test

    Rationale: A rapid strep test involves a quick throat swab that can indicate the presence of group A streptococcus bacteria, which can cause strep throat and other infections. Strep throat is a bacterial infection that affects the back of the throat and the tonsils, which become irritated and swollen, often causing a severe sore throat, especially when swallowing. A rapid strep test is done to help determine whether a sore throat is caused by a strep infection or other germs, such as a viruses.

  • Laboratory tests that are used to examine the blood and blood components to determine if they are within normal limits are:

    hematology tests (CBC)

    Rationale: Hematology is the study of blood, blood diseases, and organs that form blood. Hematology clinical laboratory tests are used to examine blood and blood components to determine if they are within normal limits. Values outside the normal limits might be signs of a disease. Hematology tests count the number of white and red blood cells and platelets. In addition, these tests measure the time necessary for blood to clot and the capability of blood to carry oxygen throughout the body. Hematology tests can also indicate inflammation and infection, and give reason for further testing to be done.

  • When a patient has an inflammation within the body, they may have an elevated:

    c-reactive protein

    Rationale: C-reactive protein (CRP) is produced by the liver, and increases when there is inflammation in the body. The CRP test measures the CRP level in the blood. A high level indicates inflammation, but cannot pinpoint the exact location in the body. If a patient has an elevated CRP level, then further testing is necessary to determine the source of inflammation.


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