| Method principle |
Chemiluminescence immunoassay (CLIA) |
Chemiluminescent Microparticle Immunoassay (CMIA) |
Electrochemiluminescence immunoassay (ECLIA) |
Chemiluminescence immunoassay (CLIA) |
| Assay principle |
Two-site sandwich immunoassay |
Two-step immunoassay |
Sandwich immunoassay |
Two-site immunoenzymatic “sandwich” assay |
| Sample volume (μL) |
50 |
60 |
10 |
35 |
| Sample stability |
< 8 hours at 24℃ |
< 24 hours at 24℃ |
< 2 hours at 24℃ |
< 8 hours at 24℃ |
| Sample storage |
< 48 hours at 2–8℃ |
< 7 days at 2–8℃ |
< 7 days at 2–8℃ |
< 48 hours at 2–8℃ |
| > 48 hours at –20℃ |
> 7 days at –20℃ |
< 6 months at –20℃ |
> 48 hours at –20℃ |
| Reagent |
Purified polyclonal rabbit anti-CEA antibody labeled with acridinium ester, monoclonal mouse anti-CEA antibody covalently coupled to paramagnetic particles |
Anti-CEA (mouse, monoclonal) coated microparticles, anti-CEA (mouse, monoclonal) acridinium-labeled conjugate |
Streptavidin-coated microparticles, Biotinylated monoclonal anti-CEA antibody (mouse/human), monoclonal anti-CEA antibody (mouse) labeled with ruthenium complex |
Anti-CEA MAb-alkaline phosphatase conjugate, anti-CEA MAb bound to paramagnetic particles |
| Calibration |
Traceable to an internal standard manufactured using highly purified material |
Traceable to an internal standard manufactured using highly purified material |
Standardized against the 1st IRP WHO Reference Standard 73/601 |
Traceable to an internal standard manufactured using highly purified material |
| Measuring range (ng/mL) |
0.5–100 |
0.5–500 (can be extended to 1,500) |
0.2–1,000 |
0.1–1,000 |
| Limit of detection (ng/mL) |
0.5 |
0.5 |
0.2 |
0.1 |
| Precision (total % CV) |
3.4–5.5 |
2.7–4.0 |
4.6–5.1 |
3.8–4.5 |
| Reference value (ng/mL) |
95th percentile; 5.0 |
93.5th percentile; < 5.0 |
95th percentile; 4.7, 5.2 |
95th percentile; 3.1–5.0 |
