Cryopreservation of virus-infected cells for use in the fluorescent antibody to membrane antigen test.

Tissue culture cells infected with varicella-zoster, respiratory syncytial, para-influenza types 1, 2, and 3, and influenza A/Texas/1/77 and A/USSR/90/77 viruses were exposed to ultraviolet light and frozen in the presence of a final concentration of 20% glycerol. These cells were quick thawed at 37 degrees C and compared with freshly prepared, living infected tissue culture cells in assays of fluorescence antibodies to membrane antigens of the infecting agents in serum, nasal wash secretions, colostrum, and breast milk. Frozen cells performed as efficiently as fresh cells as targets and retained their activity for long periods of time. Cryopreservation combined with photoinactivation of infected target cells allows this useful antibody test to be performed in routine serology laboratories.