HEp-2 cell indirect immunofluorescence assay in participating laboratories (N=36)
| Questionnaire | Category | No. of response (%) |
|---|---|---|
| How to make slides | Manual staining | 7 (19.4) |
| Using instrument (automated) | 29 (80.6) | |
| Initial screening titer of serum | 1:40 dilution | 21 (58.3) |
| 1:80 dilution | 15 (41.7) | |
| Final reportable dilution of serum if positive on screening test | 1:320 dilution | 2 (5.6) |
| 1:640 dilution | 5 (13.9) | |
| 1:1,280 dilution | 16 (44.4) | |
| 1:2,560 dilution | 7 (19.4) | |
| Other | 6 (16.7) |