Diazyme's PCT Assay
Diazyme's PCT Assay is based on a latex enhanced immunoturbidimetric method. PCT proteins in the sample bind to the specific anti-PCT antibody which is coated on latex particles, and causes agglutination. The degree of the turbidity caused by agglutination can be measured optically and is proportional to the amount of PCT in the sample. The chemistry analyzer calculates the PCT concentration of a sample by interpolation of the obtained signal of a calibration curve. The reaction is monitored at 600nm and completed within 10 minutes.
Diazyme PCT Assay Kit Configuration:
Diazyme's PCT Assay is for the quantitative determination of PCT in Serum, EDTA or Lithium Heparin plasma samples. PCT should be measured according to specific application parameters for specific chemistry analyzers. Diazyme's PCT Assay kit consists of two liquid stable reagents; R1, and R2, and the PCT calibrators and controls are packaged separately.
- Multiple instrument options available
- Reagent kit, calibrator and control sets offered separately
- Liquid Stable format
- Minimal sample of only 20 μL needed
- Cost effective
PCT should be measured according to specific application parameters for specific chemistry analyzers. Figure 10 is a general example of the assays test scheme:
The performance of Diazyme's PCT Assay was compared with the performance of a legally marketed PCT Assay using lithium heparin plasma samples (n=41). Figure 11 shows the assay correlation between Diazyme's PCT Assay on an Olympus AU 400 and a legally approved chemiluminescent immunoassay method. The individual patient serum samples used for this study were from a certified clinical laboratory. The concentrations of PCT are distributed across the reportable dynamic range (0.18-58.44 ng/mL), and the correlation coefficient between the two methods was 0.9815 with a slope of 0.9141 and y intercept of 0.3137.
Within-run precision of the Diazyme PCT Assay was evaluated. In the study, three levels of PCT controls containing 0.5 ng/mL, 2.14 ng/mL and 13.13 ng/mL PCT respectively were tested with 20 replicates in one run (Table 3).
There are seven levels of linearity sets that were prepared by diluting a sample containing high
PCT with a low sample. The assay has a linear range from 0.15-50 ng/mL. Results that exceed 60 ng/mL should be diluted with saline and retested.
The LOB, LOD, and LOQ of Diazyme's PCT Assay were determined according to CLSI (formerly NCCLS) EP17-A guidelines. The assay's LOB = 0.00 ng/mL; LOD = 0.051 ng/mL; and LOQ = 0.15 ng/mL.
To determine the level of interference from the substances normally present in the plasma, Diazyme's PCT Assay is tested with 0.6-0.8 ng/mL PCT (low), and 8-10 ng/mL PCT (high) serum samples spiked with varied concentrations of substances following Clinical and Laboratory Standards Institute (formerly NCCLS) EP7-A "Interference Testing in Clinical Chemistry": dose-response guidelines. Result: Less than 10% deviation was produced when tested up to the concentrations shown in Table 4.