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The DRI™ Tricyclics Serum Tox Assay is a homogeneous enzyme immunoassay intended for the qualitative and/or semiquantitative determination of the presence of tricyclic antidepressants (TCAs) in human serum, plasma, or urine of patients at a cutoff concentration of 300 ng/mL in patients suspected of drug overdose.

The semi-quantitative mode is for the purpose of enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method such as Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS) or permitting laboratories to establish quality control procedures.

The assay provides only a preliminary analytical test result. A more specific alternative chemical must be used to obtain a confirmed analytical result. Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS) is the preferred confirmatory method.

Clinical and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are used.

For In Vitro Diagnostic Use Only.

The DRI™ Tricyclics Serum Tox Assay is a homogeneous enzyme immunoassay using ready to-use liquid reagents. Specific tricyclic antibodies were used to detect most tricyclic antidepressants in serum, plasma, or urine. The test is based on the competition of an enzyme, glucose-6-phosphate dehydrogenase (G6PDH), labeled-drug and the drug from the sample for a fixed amount of specific antibody binding sites. In the absence of the drug from the sample, the specific antibody binds the enzyme-labeled drug and the enzyme activity is inhibited. This phenomenon creates a direct relationship between drug concentration in the sample and the enzyme activity. The enzyme activity is determined spectrophotometrically at 340 nm by measuring its ability to convert nicotinamide adenine dinucleotide (NAD) to NADH.

The DRI™ Tricyclics Serum Tox assay is supplied as a two liquid reagent kit (Reagent A and Reagent E). Thev are bottled separately within the same kit, see details below:

• Antibody/Substrate Reagent (Reagent A): Contains polyclonal anti-tricyclics . antibodies (sheep), glucose-6- phosphate (G6P), and nicotinamide adenine dinucleotide (NAD) in Tris buffer with sodium azide as a preservative.
• Enzyme Conjugate Reagent (Reagent E): Contains glucose-6-phosphate ● dehydrogenase (G6PDH) labeled with nortriptyline in Tris buffer with sodium azide as a preservative.

The provided document describes the analytical performance of the DRI™ Tricyclics Serum Tox Assay. It details various studies conducted to demonstrate its performance characteristics, but it does not explicitly state specific pass/fail acceptance criteria for each test. Instead, it presents the results of each study, implying that these results met the internal criteria used by the manufacturer for demonstrating sufficient performance and substantial equivalence to the predicate device.

Here's an analysis of the provided information, addressing your points where possible, and noting when the information is unavailable:

1. A table of acceptance criteria and the reported device performance

As mentioned, explicit acceptance criteria (e.g., "Accuracy must be >95%") are not stated in this document. The tables below summarize the reported device performance for several key analytical studies. The implication is that these reported performances were deemed acceptable for the 510(k) clearance.

• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 80/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 10/70 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/80 (Negative/Positive)

Semi-Quantitative Mode (n=80 for each concentration):

• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 80/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 19/61 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/80 (Negative/Positive)
  | Qualitative Mode (n=80 for each concentration):
• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 80/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 68/12 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/80 (Negative/Positive)

Semi-Quantitative Mode (n=80 for each concentration):

• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 80/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 73/7 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/80 (Negative/Positive)
  |
  | Precision (Reproducibility) | Qualitative Mode (n=75 for each concentration):
• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 75/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 30/45 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/75 (Negative/Positive)

Semi-Quantitative Mode (n=75 for each concentration):

• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 75/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 29/46 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/75 (Negative/Positive)
  | Qualitative Mode (n=75 for each concentration):
• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 75/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 61/14 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/75 (Negative/Positive)

Semi-Quantitative Mode (n=75 for each concentration):

• 0 ng/mL to 225 ng/mL (-100% to -25% Cutoff): 75/0 (Negative/Positive)
• 300 ng/mL (100% Cutoff): 66/9 (Negative/Positive)
• 375 ng/mL to 600 ng/mL (+25% to +100% Cutoff): 0/75 (Negative/Positive)
  |
  | Spike Recovery | Low Control (225 ng/mL, n=20): All 20 Negative (Below Cutoff)
  High Control (375 ng/mL, n=20): All 20 Positive (Above Cutoff) | Low Control (225 ng/mL, n=20): All 20 Negative (Below Cutoff)
  High Control (375 ng/mL, n=20): All 20 Positive (Above Cutoff) |
  | Dilution Linearity (Recovery)| Range 96-115% for expected values 125 ng/mL to 1000 ng/mL (average of 5 replicates) | Range 94-118% for expected values 125 ng/mL to 1000 ng/mL (average of 5 replicates) |
  | Method Comparison (Accuracy) | Qualitative Mode (n=117):
• % Negative Sample Agreement: 98% (60/61)
• % Positive Sample Agreement: 100% (56/56)
• % Total Sample Agreement: 99% (116/117)
  Semi-Quantitative Mode (n=117):
• % Negative Sample Agreement: 97% (59/61)
• % Positive Sample Agreement: 100% (56/56)
• % Total Sample Agreement: 98% (115/117) | Qualitative Mode (n=100):
• % Negative Sample Agreement: 96% (48/50)
• % Positive Sample Agreement: 98% (49/50)
• % Total Sample Agreement: 97% (97/100)
  Semi-Quantitative Mode (n=100):
• % Negative Sample Agreement: 96% (48/50)
• % Positive Sample Agreement: 98% (49/50)
• % Total Sample Agreement: 97% (97/100) |
  | Matrix Equivalency | Serum: 50 patient samples total (25 positive, 25 negative). Full agreement for K2 EDTA Plasma, K3 EDTA Plasma, Lithium Heparin Plasma, Sodium Citrate Plasma, Potassium Oxalate Plasma across qualitative and semi-quantitative modes.
  Sodium Heparin Plasma: 45 patient samples (25 positive, 20 negative). Full agreement across qualitative and semi-quantitative modes. | Not applicable (serum comparison) |
  | Interference | Spiking endogenous/exogenous/physiological substances at high concentrations into low and high controls (225 ng/mL and 375 ng/mL) showed accurate detection of controls (negative for low, positive for high), indicating no interference. (See Table 20 for list of compounds and concentrations tested). | Spiking endogenous/exogenous/physiological substances and pH variations (pH 3-11) at high concentrations into low and high controls (225 ng/mL and 375 ng/mL) showed accurate detection of controls (negative for low, positive for high), indicating no interference. (See Table 21 for list of compounds and concentrations tested). Specific gravity (1.004-1.030) also showed no interference. |
  | Specificity (Cross-Reactivity) | Extensive tables (Table 16, 18, 20) are provided listing cross-reactivity percentages for numerous structurally related and unrelated compounds in serum. The study demonstrated cross-reactivity for various TCA drugs and metabolites (e.g., Amitriptyline 100%, Desipramine 120%, Imipramine 157.9%). Minimal to no cross-reactivity (

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