12.1 Confirm the performance of the instrument or the test
procedure by analyzing a QC sample (see 7.8).
12.1.1 When QC/Quality Assurance (QA) protocols are
already established in the testing facility, these may be used to
confirm the reliability of the test result.
12.1.2 When there is no QC/QA protocol established in the
testing facility, Appendix X1 can be used as the QC/QA
system.