Lesson 15 — Microbiology and Immunology
All procedural steps, PURPOSE rationales, and topic content below are verbatim from MedCerts HLT420A Storyline modules. Quiz items have been normalized to multiple-choice format with verbatim source rationales. Reference textbook: Niedzwiecki & Pepper, Kinn's The Clinical Medical Assistant, 15th ed., Chapter 35. No outside material added.
- Differentiate the physician office laboratory (POL) and the reference laboratory
- Discuss collection and transport of specimens
- Classify types of CLIA-waived testing related to microbiology and immunology
- Demonstrate rapid strep and mononucleosis testing
- Describe the function of the microbiology laboratory
- Summarize the potential role of the medical assistant in microbiology and immunology
CLIA-Waived Rapid Strep
Goal: Perform a CLIA-waived rapid Strep test.
- Test cassette
- Sterile rayon swabs
- Reagents
- Gown
- Eye protection
- Gloves
- Biohazard waste container
-
Greet the patient.
-
Confirm patient's full name and date of birth.
-
Explain the procedure.
-
Wash hands or use hand sanitizer.
-
Put on proper personal protective equipment, or P-P-E, including gown, eye protection, and gloves.
-
Confirm the physician's order or lab requisition.
-
Prepare all supplies and equipment.
-
Bring reagents to room temperature.
-
Remove the test cassette from the foil pouch and place it on a flat surface.
-
Collect a throat specimen, gently gliding the swab over the tonsillar pillars.
-
Place swab into the holding chamber on the cassette.
-
Mix reagent and add drops to the holding well according to manufacturer's instructions.
-
Wait five minutes, or as directed by the manufacturer, to read results.
-
Read results by identifying the blue control line and any pink line that indicates a positive result.
-
Report the results to the physician so a diagnosis can be documented.
-
Discard swab and test cassette in a biohazard waste container.
-
Disinfect the work areas.
-
Remove P-P-E and wash hands.
-
Document results in the patient record.
The CLIA-waived rapid Strep test is commonly performed by the medical assistant in the physician office laboratory (POL). CLIA-waived Strep tests are used to rapidly detect or rule out a diagnosis of Strep throat. The test may be performed by a trained medical assistant. The patient awaits the results and is treated if necessary.
The standard Strep test kit includes: An individual test cassette, Sterile rayon swabs, And reagents, or solutions for the test. Reagents should be brought to room temperature.
A blue control line indicates a properly working test. If Streptococcus pyogenes are present, a pink line will also appear. The pink line indicates a positive result.
Knowledge-check items
Click an answer to lock it in — you'll see the rationale below. Reset any time to re-attempt. Items originally formatted as true/false, fill-in-blank, or drag-and-drop have been normalized to multiple choice; the source format is noted in the eyebrow.
L15-01 · CLIA-Waived Rapid Strep
"Prior to testing, greet the patient. Confirm patient's full name and date of birth. Explain the procedure. Wash hands or use hand sanitizer. Put on proper personal protective equipment."
The correct sequence begins with patient preparation and safety measures, followed by equipment preparation, specimen collection, testing, result interpretation, and proper cleanup and documentation. This order ensures patient safety and test accuracy.
"A blue control line indicates a properly working test."
The blue control line is an internal quality control indicator that verifies the test was performed correctly and the reagents functioned as intended, regardless of whether the test is positive or negative.
"If Streptococcus pyogenes are present, a pink line will also appear. The pink line indicates a positive result."
When both a blue control line and a pink line are visible, the presence of Streptococcus pyogenes bacteria has been detected, indicating a positive diagnosis of Strep throat.
"Wait five minutes, or as directed by the manufacturer, to read results."
The five-minute wait time allows sufficient time for the antigen-antibody reaction to occur and for the result lines to develop clearly. Always follow the specific manufacturer's instructions, as some tests may have different timing requirements.
"Put on proper personal protective equipment, or P-P-E, including gown, eye protection, and gloves."
Full PPE including gown, eye protection, and gloves is required to protect against potential exposure to blood and oral secretions during specimen collection and test handling.
"After the test is complete, discard swab and test cassette in a biohazard waste container."
Biohazard waste containers are required for any materials that have contacted body fluids or potentially infectious materials, including used test cassettes from Strep testing.