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• Pipetting devices and machines should be validated before routine use, and validation reports should be available.
• Calibration of the pipetting devices should be performed periodically and should be documented.
9.5.1.3 Testing and post-analytical procedures
Testing of blood components should be carried out in accordance with the recommendations of the manufacturer of reagents and test kits.
Modifi cations to the manufacturer’s instructions or reagents for donor screening tests should be validated. Where required, prior approval of the
NRA should be obtained before the modifi ed method is used for release of a blood component. Laboratory reagents intended for prolonged use
should be marked with the preparation date, expiry date, specifi c storage conditions and signature of the person who prepared them. Instructions for
use and storage should be followed.
Screening algorithms should be precisely defi ned in writing i.e. standard operating procedures to deal with initially reactive specimens and to
resolve discrepancies in results after retesting. All available measures should be taken to ensure that blood and blood components that are repeat
reactive upon screening for an infectious disease marker are excluded from therapeutic use. Repeat reactive material should be stored away from all
other blood components in a separate dedicated storage area. Such material should eventually be destroyed to prevent inadvertent re-entry into the
transfusion chain.
Test algorithms should provide details for appropriate confi rmatory testing. In the case of repeatedly reactive results, clearly defi ned follow-up
instructions should be followed. Actions include:
— notifi cation and deferral of the donor; — disposal of the indicated donation and of concurrent products;
— tracing and destruction of products which have not yet expired.
If products from the donor have been processed for further manufacture, there should be a procedure in place to assess both the safety of the
manufactured products and whether a recall is needed.
Procedures for donor- andor recipient-initiated look-backs should also be defi ned. Look-backs should be designed in such a way that the transfusion
chain of donor–blood or blood product–recipient can be unequivocally reconstructed. The procedure should comprise notifi cation and counselling
action where indicated.
The following practical points should be considered in order to ensure that the equipment used for virology testing performs appropriately:
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• There should be a mechanism to ensure positive sample identifi cation and linkage to the donor. The preferred method is by sample tubes with barcodes.
• Ideally, the addition of reagent and samples and the testing process should be automated, in order to minimize risk of human errors and to ensure full
traceability of the testing process. • If addition of reagents and samples or preparation of test plates are
done manually, full documentation of each addition step should be kept, ensuring identifi cation of the test plate and the location of the reaction
well.
9.5.1.4 Test interpretation and follow-up of reactive results
