TABLE 1.
Characteristics of ELISAs for detection of T. pallidum antibodiesa
| Trade name (company) | Trepanostika (Organon) | ICE Syphilis (Murex) | Enzygnost Syphilis (Behring) | Pathozyme Syphilis Competition (Omega) | Bioelisa Syphilis (Biokit) | Trep-Chek (Phoenix) | TmpA-ELISA (Eurodiagnostica) | Captia Syphilis G (Trinity) | Captia Syphilis M (Mercia) | 19S IgM FTA-ABS |
|---|---|---|---|---|---|---|---|---|---|---|
| Predilution (μl; serum + diluent) | No | No | No | No | Yes (10 + 200) | Yes (20 + 380) | Yes (20 + 400) | Yes (10 + 200) | Yes (20 + 1,000) | No |
| (Prediluted) serum (μl) | 30 | 50 | 25 | 25 | 100 | 100 | 100 | 210 | 100 | |
| Diluent (μl) | 0 | 50 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Dilution | 1:1 | 1:2 | 1:1 | 1:1 | 1:21 | 1:20 | 1:21 | 1:21 | 1:51 | 1:10 |
| Antigen | T. pallidum lysate | Rec. TpN15 | T. pallidum lysate | T. pallidum lysate | Rec. TpN15 | Cocktail of Rec. antigens | Rec. TmpA | T. pallidum lysate | T. pallidum lysate | Whole treponemes |
| Rec. TpN17 | Rec. TpN17 | |||||||||
| Rec. TpN47 | ||||||||||
| Method | Competitive | Capture | Competitive | Capture | Sandwich | Sandwich | Sandwich | Sandwich | Capture | Immunofluorescence |
| No. of incubations | 2 | 3 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 2 |
| Duration of all incubations (min) | 105 | 120 | 120 | 115 | 120 | 75 | 150 | 90 | 150 | 60 |
| No. of washings | 1 | 2 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 1 |
| Cutoff | NC × 0.7 | NC + 0.200 | NC × 0.7 | Low positive control | NC + 0.300 | Cutoff control | NC + 0.100 | NC × 2 | Low positive control | |
| Detection of Ig | IgM + IgG | IgM + IgG | IgM + IgG | IgM + IgG | IgM + IgG | IgG | IgM + IgG | IgG | IgM | IgM |
a
Rec, recombinant; NC, negative control; ∗, overall dilution factor of IgM fraction of serum.