Use of frozen neutrophils in serological testing

We describe an immunofluorescence test to detect neutrophil-specific antibodies using neutrophils fixed to a slide and frozen prior to use. In titration studies using NA1, NA2 and NB1 antisera the technique was less sensitive than the standard immunofluorescence test but did enable slides to be stored for at least 5 months with no loss of NA1, NA2 and NB1 antigens. This technique can be used as a simple alternative to neutrophil cytoplasts for the identification of neutrophil antibodies. However, its use as a screening test in neutrophil serology is limited by the occurrence of false negative reactions with weakly reactive antisera.