(22 days)
Reagents: ST AIA-PACK Homocysteine is designed for IN VITRO DIAGNOSTIC USE ONLY for the quantitative measurement of homocysteine in human serum, heparinized plasma or EDTA plasma using a Tosoh AlA System Analyzer. Homocysteine measurements are used in the diagnosis and treatment of hyperhomocysteinemia or homocystinuria. Calibrators: ST AIA-PACK Homocysteine Calibrator Set is intended for IN VITRO DIAGNOSTIC USE ONLY for the callbration of the ST AIA PACK Homocysteine assay using a Tosoh AIA System Analyzer. Controls: The AIA-PACK Homocysteine Control Set is intended for IN VITRO DIAGNOSTIC USE ONLY for performing quality control procedures with the ST AIA-PACK Homocysteine Assay.
The ST AIA-PACK Homocysteine is a competitive enzyme immunoassay which, after sample pretreatment, is performed entirely in the ST AIA-PACK Homocysteine test cups. Oxidized homocysteine is reduced by tris (2-carboxyethyl) phosphine (TCEP) to the free form and converted to S-adenosyl-L-homocysteine (SAH) by the SAH hydrolase and excess adenosine prior to the immunoassay. SAH present in the pretreated sample competes with immobilized SAH on magnetic beads for binding sites of the enzyme-labeled anti-SAH mouse monoclonal antibody. The magnetic beads are washed to remove unbound anti-SAH mouse monoclonal antibody and are then incubated with a fluorogenic substrate, 4-methylumbelliferyl phosphate (4MUP). The rate of fluorescence produced by the enzyme reaction indicates the amount of enzyme-labeled anti-SAH mouse monoclonal antibody. The amount of antibody that binds to the beads is inversely proportional to the homocysteine concentration in the test sample. A standard curve is constructed, and unknown sample concentrations are calculated using this curve.
Here's a breakdown of the acceptance criteria and study information for the ST AIA-PACK Homocysteine device, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria Category | Specific Criteria/Study Goal | Reported Device Performance |
|---|---|---|
| Precision | Within-run (Intra-assay): To demonstrate consistency of results within a single run. | Coefficient of Variation (CV) ranged from 3.1% to 4.3% across various sample types (EDTA Plasma, HEP Plasma, Serum) and homocysteine concentrations. |
| Total Precision (Inter-assay): To demonstrate consistency of results across multiple runs and days. | Coefficient of Variation (CV) ranged from 3.6% to 5.0% across various sample types (EDTA Plasma, HEP Plasma, Serum) and homocysteine concentrations. | |
| Linearity/Reportable Range | To demonstrate that the assay accurately measures homocysteine concentrations across a specified range. | Demonstrated to be linear from 0.5 to 50.0 µmol/L. |
| Detection Limit | To determine the lowest concentration of homocysteine that can be reliably detected. | Limit of Detection (LoD) estimated at 0.334 µmol/L. |
| Interference | To ensure that common endogenous and exogenous substances do not significantly affect assay results (recovery within 100 +/- 10%). | No interference observed from: Hemoglobin (up to 1445 mg/dL), free bilirubin (up to 18 mg/dL), conjugated bilirubin (up to 18 mg/dL), Lipemia (up to 1667 mg/dL triglyceride), Added protein (up to 50 mg/ml human g-globulin), Ascorbic acid (up to 20 mg/dL), EDTA-2K (up to 5.0 mg/mL), Heparin (up to 100 U/mL). |
| Specificity (Cross-reactivity) | To determine the extent to which other compounds similar to homocysteine are incorrectly identified as homocysteine. | Cross-reactivity: |
§ 862.1377 Urinary homocystine (nonquantitative) test system.
(a)
Identification. A urinary homocystine (nonquantitative) test system is a device intended to identify homocystine (an analogue of the amino acid cystine) in urine. The identification of urinary homocystine is used in the diagnosis and treatment of homocystinuria (homosystine in urine), a heritable metabolic disorder which may cause mental retardation.(b)
Classification. Class II.