Table 14. New batch of reagents.

Recommended practice	Evaluation of the new reagent batch before production. New reagent lot evaluated from patient samples (at least 3) or other argumentative strategy (21). Evaluation of the new reagent lot with “fresh” patient samples only for tests with uncertain IQC commutability (mainly tumour markers, hormonology).
Acceptable practice	Evaluation of the new reagent at the start of production, but risk of disruption of activity and delay of results, with possible loss of opportunity for the patient (for some tests) and the importance of support to control this risk.
Unacceptable practice	No traceability of exchanges of reactive practice batches. No evaluation of a new reagent lot in a series between 2 IQCs (calibration validated without going through all IQC levels). No backup solution for critical analytes (volume, sample storage time).
IQC – internal quality control.