AHG REAX

• Causes of FALSE-POSITIVE REACTIONS

  • Contamination of reagents
  • Over Centrifugation
  • Direct agglutination by strong agglutinins
  • Over-incubation with enzyme-treated cells
  • Improper use of enhancement reagents
  • Saline stored in glass or metal containers
• Causes of FALSE-NEGATIVE REACTIONS

  • Reagent failure
  • Improper washing
  • Failure to add antiglobulin reagents
  • Improper centrifugation
  • Serum/cell ratio too low
  • Delayed washing (elution of weakly attached antibody)