Introduction to Quality Control in Diagnostic Lab

Step 1: Monitoring Critical Parameters:

• Monitor sterility, media quality, and sensitivity test results using control strains like E. coli and S. aureus.
• Expected Values:
  • Incubator Temperature: 35-37°C
  • Zone Diameter for Antibiotic Sensitivity: Based on CLSI guidelines for specific control strains.

Step 2: Recording QC Data:

• For each batch of media or sensitivity test, record the results on LJ charts. Ensure that control strains yield consistent and accurate results.

Step 3: Applying Westgard Rules:

• If you see a trend or a sudden shift in zone diameters or media growth results, apply Westgard rules to detect any errors. For example, if two consecutive results fall outside the expected range, apply the 2-2s rule and investigate media quality or incubation conditions.