Controls

• Positive and negative controls should be used on a regular basis
• At a minimum, they should be used when starting up an analyser, changing reagent lot numbers, when changing batches, and 12-hourly.
• A diluent control must always be used when:
  • Specified by the manufacturer.
  • There is evidence that a cold auto-antibody is present.
  • A patient’s sample is agglutinated.

Reagent	Positive Control Cell	Negative Control Cell
Anti-A	A	B
Anti-B	B	A
Anti-D	D positive	D negative

Other Resources:

• BCSH Guideline: Pre-Transfusion Compatability Procedures (2012)