What does validation of equipment or a method mean in practice? Explain using using the example of validating a semi-automated instrument to determine patient ABO groups.

From a practical perspective, validating equipment and methods means that laboratories must demonstrate and document that equipment and methods work as expected under real-world conditions before they are implemented.

To validate a semi-automated instrument to determine ABO groups, a sample protocol would be to test an appropriate number of samples to include

• the range of sample types encountered in the lab (e.g., clotted, EDTA)
• samples with
  • normal ABO groups
  • ABO discrepancies (as many types as possible)
  • A₂ and A₂B groups
  • weak subgroups (if available)