Histology Certification Quality Control and Quality Assurance 2 — Questions and Answers
Question 1: A negative control in immunohistochemistry staining is used to:
- Confirm that a known antigen is detectable by the antibody
- Verify that non-specific background staining is absent (Correct answer)
- Test the effectiveness of the hematoxylin counterstain
- Assess the adequacy of tissue fixation time
Correct answer: Verify that non-specific background staining is absent
A negative control replaces the primary antibody with diluent or irrelevant antibody to confirm that any staining observed in test slides is specific and not non-specific background.
Question 2: In histology QC, a 'reagent blank' control is used to detect:
- Contamination or non-specific staining produced by reagents alone (Correct answer)
- Variation in the thickness of tissue sections cut on the microtome
- Inadequate fixation of the tissue specimen
- Miscalibration of the automated stainer temperature
Correct answer: Contamination or non-specific staining produced by reagents alone
A reagent blank omits the tissue and runs all reagents on a blank substrate to detect background staining from contaminated or degraded reagents.
Question 3: According to CAP accreditation requirements, histology QC records must be retained for a minimum of:
- 1 year
- 2 years (Correct answer)
- 5 years
- 10 years
Correct answer: 2 years
CAP requires QC records to be retained for at least 2 years, though many labs keep records longer to comply with state regulations or institutional policies.
Question 4: Which of the following best describes 'intralaboratory QC' in histology?
- Sending samples to an external reference laboratory for comparison testing
- Monitoring and controlling analytical processes within the same laboratory (Correct answer)
- Reviewing QC benchmark data submitted by peer laboratories nationally
- Submitting stained slides to CAP for external proficiency evaluation
Correct answer: Monitoring and controlling analytical processes within the same laboratory
Intralaboratory QC refers to the internal processes a lab uses to monitor its own performance, including control slides, reagent checks, instrument maintenance logs, and QC documentation.
Question 5: What is a primary advantage of using a tissue microarray (TMA) for IHC quality control?
- It replaces the need for routine H&E staining controls
- It allows simultaneous testing of multiple tissues and antibodies on a single section (Correct answer)
- It measures the exact pH of staining solutions during the run
- It calibrates the cryostat to maintain consistent section temperature
Correct answer: It allows simultaneous testing of multiple tissues and antibodies on a single section
TMAs contain multiple tissue cores on one slide, enabling efficient simultaneous QC of many antibodies and tissue types with minimal reagent consumption.
Question 6: A complete corrective action record in histology QC documentation must include:
- Only the date and technician name associated with the problem
- The root cause, corrective action taken, and verification that the problem was resolved (Correct answer)
- Only a list of all reagents used during the failed staining run
- The pathologist's signature approving the corrective action plan
Correct answer: The root cause, corrective action taken, and verification that the problem was resolved
Complete corrective action documentation requires the root cause, the specific action taken, and follow-up verification that the corrective action was effective and the problem will not recur.
Question 7: CLIA regulations require laboratories performing moderate- or high-complexity testing to:
- Use only CAP-approved reagents and antibody clones for all tests
- Establish and follow written quality control procedures (Correct answer)
- Submit daily QC results electronically to the FDA for review
- Perform external proficiency testing at least once per week
Correct answer: Establish and follow written quality control procedures
CLIA mandates that all laboratories performing moderate- or high-complexity testing must have written QC procedures to ensure the accuracy and reliability of patient results.
Histology Certification Quality Control and Quality Assurance 2
A negative control in immunohistochemistry staining is used to: