Certified Medical Assistant Clinical Procedures and Specimen Handling Questions and Answers — Questions and Answers
Question 1: A medical assistant is preparing to perform a venipuncture. Which of the following is the correct order of draw to prevent cross-contamination of additives?
- Light Blue, Red, Green, Lavender
- Red, Light Blue, Lavender, Green
- Yellow (Blood Culture), Light Blue, Red, Green, Lavender, Gray (Correct answer)
- Gray, Lavender, Green, Red, Light Blue
Correct answer: Yellow (Blood Culture), Light Blue, Red, Green, Lavender, Gray
The correct order of draw is established by CLSI to prevent the transfer of additives from one tube to the next, which could alter test results. The sequence begins with sterile specimens (Yellow for blood cultures), followed by coagulation tubes (Light Blue), serum tubes (Red), heparin tubes (Green), EDTA tubes (Lavender), and finally glycolytic inhibitor tubes (Gray).
Question 2: When instructing a female patient on how to collect a clean-catch midstream urine specimen for a culture and sensitivity test, which of the following instructions is most important to prevent contamination?
- Collect the first part of the urine stream to ensure the sample is concentrated.
- Wipe the genital area from back to front using a single antiseptic towelette.
- Separate the labia and cleanse the area from front to back before voiding a small amount into the toilet and then collecting the sample. (Correct answer)
- Fill the collection cup to the very top to provide an ample sample.
Correct answer: Separate the labia and cleanse the area from front to back before voiding a small amount into the toilet and then collecting the sample.
To obtain a specimen free from external bacteria, the patient must be instructed to separate the labia and use an antiseptic wipe to clean the urethral meatus and surrounding area in a front-to-back motion. Voiding the initial stream of urine into the toilet helps flush out contaminants from the urethra before the 'midstream' sample is collected in the sterile container.
Question 3: A medical assistant is handling a specimen for a throat culture. Which of the following actions is essential for maintaining the viability of the microorganisms?
- Refrigerating the specimen immediately after collection.
- Placing the collection swab into the transport medium and keeping it at room temperature. (Correct answer)
- Exposing the swab to air for several minutes to dry before packaging.
- Labeling the container with only the patient's name.
Correct answer: Placing the collection swab into the transport medium and keeping it at room temperature.
Throat culture swabs should be placed in a sterile transport medium to keep the microorganisms alive until they can be cultured in the laboratory. Most microbiology specimens, including throat cultures, should be transported at room temperature to ensure the integrity of the potential pathogens.
Question 4: A patient arrives for a pre-employment drug screening. To ensure the integrity of the specimen and the legal defensibility of the test, the medical assistant must follow which protocol?
- Patient privacy protocol
- Standard universal precautions
- CLIA waived test procedure
- Chain of custody protocol (Correct answer)
Correct answer: Chain of custody protocol
A chain of custody is a legal and procedural document that tracks the specimen from the moment of collection to its final testing and reporting. This process ensures that the specimen is properly identified, has not been tampered with, and that all handling is documented, which is crucial for legal and employment-related drug testing.
Question 5: Which of the following point-of-care tests is a medical assistant permitted to perform under a CLIA Certificate of Waiver?
- Blood gas analysis
- Pap smear cytology
- Urine pregnancy test (Correct answer)
- Microscopic urinalysis
Correct answer: Urine pregnancy test
CLIA-waived tests are simple laboratory examinations and procedures that have a low risk of an erroneous result. A urine pregnancy test is a common example of a CLIA-waived test that medical assistants are trained and authorized to perform in a physician's office laboratory. The other options are considered moderate to high-complexity tests.
Question 6: When preparing a microbiology specimen for transport to an outside laboratory, how should the medical assistant package the sample?
- In a paper bag with the requisition form stapled to the outside.
- Wrapped in gauze and placed in the courier's general pickup box.
- In a securely sealed, leak-proof primary container placed inside a labeled biohazard transport bag. (Correct answer)
- On ice in a styrofoam cooler, regardless of the specimen type.
Correct answer: In a securely sealed, leak-proof primary container placed inside a labeled biohazard transport bag.
Proper handling and transport are critical for specimen viability and safety. The standard procedure is to place the securely closed primary container into a leak-proof biohazard bag to prevent any potential leakage and contamination. The requisition form should be placed in the outside pocket of the bag to keep it separate from the specimen.
A medical assistant is preparing to perform a venipuncture.
Which of the following is the correct order of draw to prevent cross-contamination of additives?