(62 days)
The DiaSorin LIAISON® Vitamin B12 assay uses chemiluminescent immunoassay (CLIA) technology for the quantitative determination of Vitamin B12 in human serum, SST serum and lithium heparin plasma. Measurements obtained by this device are used in the diagnosis and treatment of anemia's of gastrointestinal malabsorption. Assay results should be used in conjunction with other clinical or laboratory data to assist the clinician in making individual patient management decisions.
The assay must be performed on the LIAISON® XL Analyzer.
The LIAISON® Vitamin B12 assay is a competitive chemiluminescence immunoassay (CLIA) for quantitative determination of Vitamin B12 is serum. SST serum and lithium heparin plasma. During the first incubation, Vitamin B12 is dissociated from its binding protein. After the initial incubation of 10.5 minutes. Vitamin B12 binds to an intrinsic factor on the solid phase. After a second incubation of 10.5 minutes, a Vitamin B12 linked to an isoluminol derivative is added to compete with the Vitamin B12 in the sample. After a third incubation of 5.25 minutes, the unbound material is removed with a wash cycle. Subsequently, the starter reagents are added to initiate a flash chemiluminescent reaction. The light signal is measured by a photomultiplier as relative light units (RLU) and is inversely proportional to the concentration of Vitamin B12 present in calibrators, controls, or samples.
Here is the information about the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a tabulated format with specific pass/fail thresholds for each performance characteristic. Instead, it describes various performance studies and their results. The "reported device performance" below summarizes the key findings from these studies. It is implied that these findings meet the FDA's requirements for substantial equivalence.
| Performance Characteristic | Reported Device Performance |
|---|---|
| Method Comparison | LIAISON® Vitamin B12 = 0.97 (Reference Method) + 6.25; R = 0.985 (N=155). This indicates strong agreement with a commercially available reference method. |
| Sample Matrix Equivalence | SST serum vs. Serum (N=48): Constant Bias = 8.21 (95% CI: 2.14 to 16.56), Proportional Bias = 0.97 (95% CI: 0.94 to 0.99), R² = 0.996. Lithium Heparin vs. Serum (N=48): Constant Bias = 14.78 (95% CI: 1.09 to 29.87), Proportional Bias = 1.10 (95% CI: 1.05 to 1.15), R² = 0.988. These results demonstrate equivalence across different sample types. |
| Reference Range | Observed Range (N=166, US population): 107.2 pg/mL – 653.3 pg/mL (2.5th to 97.5th Percentile). Median: 318.5 pg/mL. Establishes expected values for a healthy population. |
| Precision | Intra-Run %CVs: Ranged from 3.4% to 5.2%. Total %CVs: Ranged from 6.7% to 10.0% across 8 samples/controls with varying mean concentrations (240 pg/mL to 1262 pg/mL). Indicates good reproducibility and repeatability. |
| Linearity | Serum: Observed Vitamin B12 = 1.076x + 6.896; R = 0.998 SST Serum: Observed Vitamin B12 = 1.009x + 0.224; R = 0.999 Lithium Heparin plasma: Observed Vitamin B12 = 1.029x - 0.095; R = 0.996. Shows linearity across the measuring range. |
| Recovery | Mean Recovery: 100% (Individual sample recoveries ranged from 95% to 106% across 5 high/low concentration pairs). Demonstrates accurate recovery of Vitamin B12. |
| Analytical Specificity (Cross-Reactivity) | Dicyanocobinamide (10,000 pg/mL): -0.19% Cross Reactivity. Shows minimal cross-reactivity with a related substance. |
| Analytical Specificity (Interference) | No interference demonstrated at specified high concentrations for Hemoglobin (300 mg/dL), Bilirubin (40 mg/dL), Triglycerides (3,000 mg/dL), Cholesterol (500 mg/dL), Albumin (12 g/dL), Human IgG (12 g/dL), HAMA (1387.5 ng/mL), Rheumatoid Factor (1035 IU/mL), Acetaminophen (20 mg/dL), Acetylsalicylic Acid (65 mg/dL), Ibuprofen (50 mg/dL), Biotin (2 mg/mL). |
| Limit of Blank (LoB) | ≤ 38.7 pg/mL |
| Limit of Detection (LoD) | 51.2 pg/mL |
| Limit of Quantitation (LoQ) | 55 pg/mL |
| Stability | Reagent Integral Open vial on system: 42 days Reagent Integral Open vial 2-8°C: 28 days Calibration curve: 21 days |
| Traceability | Traceable to an in-house standard preparation (pg/mL). |
2. Sample Sizes Used for the Test Set and Data Provenance
- Method Comparison: 155 samples. Data provenance not explicitly stated (e.g., country of origin) but implied to be patient samples. Retrospective or prospective is not specified, but typically method comparison uses existing samples.
- Sample Matrix Comparison: 48 matched patient sets (serum, SST serum, lithium heparin plasma samples). Data provenance not specified.
- Reference Range: 166 prospectively collected serum samples from apparently healthy adults aged 21-59. Provenance: United States; mixed ethnic backgrounds (30% Caucasian, 31% African Americans, 39% Hispanics). Prospective.
- Precision: Six (6) serum samples and two (2) kit controls.
- Linearity: One (1) high sample of each specimen type (serum, lithium heparin plasma).
- Recovery Study: Five (5) high concentration serum samples and five (5) low concentration serum samples.
- Cross-Reactivity Studies: Controlled spiked samples.
- Interference Studies: Controlled spiked samples.
- Limit of Blank, Limit of Detection, Limit of Quantitation: Not explicitly stated, typically involves multiple replicates of blank and low-concentration samples.
The document refers to various CLSI (Clinical and Laboratory Standards Institute) guidelines, which are commonly used for prospective, standardized studies in laboratory settings.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The concept of "experts" to establish "ground truth" as typically understood in AI/imaging studies (e.g., radiologists interpreting images) does not apply directly here. The ground truth for this device (a Vitamin B12 assay) is established through:
- Measurement by a commercially available reference method: For method comparison studies, the predicate device's results serve as a reference.
- Defined concentrations / spiking: For linearity, recovery, analytical specificity, and LoD/LoQ studies, the ground truth is based on accurately prepared samples with known concentrations.
- Clinical criteria: For the reference range study, healthy status was determined by inclusion/exclusion criteria related to medical history, medication use, and fasting status. These criteria are established by medical consensus, not by individual experts "adjudicating" each case.
Therefore, the number and qualifications of experts in the traditional sense are not applicable here.
4. Adjudication Method for the Test Set
Not applicable. As this is an in-vitro diagnostic (IVD) assay quantifying a biomarker, the "ground truth" is determined by established analytical methods, reference materials, or clinical definitions, rather than human interpretation requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This type of study is typically performed for diagnostic imaging devices where human readers interpret medical images with and without AI assistance. This document describes an in-vitro diagnostic device that measures a biomarker in a laboratory setting, not an imaging device.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the studies described are standalone (algorithm/device only) performance studies. The entire document focuses on the analytical performance of the LIAISON® Vitamin B12 assay itself, without any human interpretation of its results being part of the primary performance evaluation. The device generates quantitative values for Vitamin B12, and its accuracy, precision, linearity, etc., are evaluated directly.
7. The Type of Ground Truth Used
The ground truth used varies by study:
- Method Comparison: "Reference Method" (another commercially available Vitamin B12 assay, the predicate device, Beckman Coulter Access Vitamin B12 assay, K140496).
- Sample Matrix Comparison: Comparison against its own measurement in serum, which is considered the reference matrix.
- Reference Range: Clinical criteria for "apparently healthy adults" (absence of anemias, B12 deficiency, IBD, celiac disease, malabsorption, specific medication use, pregnancy, etc.).
- Precision, Linearity, Recovery, Analytical Specificity (Cross-Reactivity & Interference), LoB, LoD, LoQ: Defined concentrations in spiked or diluted samples, or blank samples. These are established through gravimetric/volumetric preparation of standards and controls.
8. The Sample Size for the Training Set
The document does not provide information about a "training set" in the context of machine learning. This device is a chemiluminescent immunoassay (CLIA), which is a traditional laboratory analytical method, not an AI/machine learning algorithm that requires training data in the same way. The assay development would involve optimizing reagents and protocols, but this is a different process than "training" an algorithm.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as this device does not utilize a training set in the machine learning sense. The "ground truth" (i.e., known concentrations) during the development and optimization of such an assay would be established through primary analytical methods, reference materials, and standardized analytical practices during the assay's R&D phase.
{0}------------------------------------------------
Image /page/0/Picture/0 description: The image shows the logo for the U.S. Food & Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services seal on the left and the FDA acronym followed by the full name of the agency on the right. The FDA part of the logo is in blue, with the acronym in a solid blue square and the agency name in a lighter blue. The text reads "FDA U.S. FOOD & DRUG ADMINISTRATION".
October 2, 2019
DiaSorin Inc. Mari Meyer Regulatory Affairs Specialist 1951 Northwestern Ave. P.O. Box 285 Stillwater, MN 55082-0285
Re: K192064
Trade/Device Name: LIAISON® Vitamin B12 Regulation Number: 21 CFR 862.1810 Regulation Name: Vitamin B12 test system Regulatory Class: II Product Code: CDD Dated: July 31, 2019 Received: August 5, 2019
Dear Mari Meyer:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's
{1}------------------------------------------------
requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
Kellie B. Kelm, Ph.D. Acting Director Division of Chemistry and Toxicology Devices OHT7: Office of In Vitro Diagnostics and Radiological Health Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
{2}------------------------------------------------
Indications for Use
510(k) Number (if known)
Device Name LIAISON® Vitamin B12
Indications for Use (Describe)
The DiaSorin LIAISON® Vitamin B12 assay uses chemiluminescent immunoassay (CLIA) technology for the quantitative determination of Vitamin B12 in human serum, SST serum and lithium heparin plasma. Measurements obtained by this device are used in the diagnosis and treatment of anemia's of gastrointestinal malabsorption. Assay results should be used in conjunction with other clinical or laboratory data to assist the clinician in making individual patient management decisions.
The assay must be performed on the LIAISON® XL Analyzer.
Type of Use (Select one or both, as applicable)
Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
{3}------------------------------------------------
510(k) Summary
LIAISON® Vitamin B12
This summary of 510(k) safety and effectiveness information is submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92
1. 510(k) Number: K192064
-
Applicant: Mari Meyer DiaSorin Inc. 1951 Northwestern Avenue, P.O. Box 285, Stillwater, MN 55082-0285 Office Number: 651-351-5635; Fax Number: 651-351-5669 Email: mari.meyer@diasorin.com
-
Date: September 25, 2019
4. Proprietary and Established Names:
LIAISON® Vitamin B12
5. Requlatorv Information:
LIAISON® Vitamin B12
Regulation Section: 21 CFR 862.1810 Classification: Class II Product Code: CDD Panel: Clinical Chemistry (75)
6. Predicate Device(s):
The predicate device used to demonstrate substantial equivalence to the LIAISON® Vitamin B12 assay is the Beckman Coulter Access Vitamin B12 assay previously FDA cleared under (K140496).
7. Device Description:
The LIAISON® Vitamin B12 assay is a competitive chemiluminescence immunoassay (CLIA) for quantitative determination of Vitamin B12 is serum. SST serum and lithium heparin plasma. During the first incubation, Vitamin B12 is dissociated from its binding protein. After the initial incubation of 10.5 minutes. Vitamin B12 binds to an intrinsic factor on the solid phase. After a second incubation of 10.5 minutes, a Vitamin B12 linked to an isoluminol derivative is added to compete with the Vitamin B12 in the sample. After a third incubation of 5.25 minutes, the unbound material is removed with a wash cycle. Subsequently, the starter reagents are added to initiate a flash chemiluminescent reaction. The light signal is measured by a photomultiplier as relative light units (RLU) and is inversely proportional to the concentration of Vitamin B12 present in calibrators, controls, or samples.
{4}------------------------------------------------
8. Intended Use:
The DiaSorin LIAISON® Vitamin B12 assay uses chemiluminescent immunoassay (CLIA) technology for the quantitative determination of Vitamin B12 in human serum, SST serum and lithium heparin plasma. Measurements obtained by this device are used in the diagnosis and treatment of anemia's of gastrointestinal malabsorption. Assay results should be used in conjunction with other clinical or laboratory data to assist the clinician in making individual patient management decisions.
The assay must be performed on the LIAISON® XL Analyzer.
9. Indication(s) for Use:
Same as Intended Use
10. Substantial Equivalence Information:
A comparison of the similarities and differences between the LIAISON® Vitamin B12 assay and the predicate Beckman Coulter Access Vitamin B12 assay is provided in the following table:
| Assay Similarities and Differences | |||
|---|---|---|---|
| Characteristic | Candidate DeviceLIAISON® Vitamin B12 | Predicate DeviceBeckman Coulter AccessVitamin B12 (K140496) | |
| Intended Use | The DiaSorin LIAISON® VitaminB12 assay uses chemiluminescentimmunoassay (CLIA) technologyfor the quantitative determinationof Vitamin B12 in human serum,SST serum and lithium heparinplasma. Measurements obtainedby this device are used in thediagnosis and treatment ofanemia's of gastrointestinalmalabsorption. Assay resultsshould be used in conjunction withother clinical or laboratory data toassist the clinician in makingindividual patient managementdecisions.The assay must be performed onthe LIAISON® XL Analyzer. | The Access Vitamin B12assay is a paramagneticparticle, chemiluminescentimmunoassay for thequantitative determination ofvitamin B12 levels in humanserum and plasma (heparin)using the AccessImmunoassay Systems. | |
| Measured Analyte | Vitamin B12 | Same | |
| Assay Type | Chemiluminescenceimmunoassay | Same | |
| Results | Quantitative | Same |
{5}------------------------------------------------
| Characteristic | Candidate DeviceLIAISON® Vitamin B12 | Predicate DeviceBeckman Coulter AccessVitamin B12 (K140496) |
|---|---|---|
| Sample Type | Human serum, SST serum andlithium heparin plasma | Human serum and heparinplasma |
| Sample Size | 100 µL | 45 µL |
| Storage | 2-8°C | 2-10°C |
| OperatingPrinciple | Automated ChemiluminescentImmunoassay (CLIA) | Same |
| Solid Phase | Magnetic particles coated intrinsicfactor | Paramagnetic particles coatedwith goat anti-mouse IgG |
| Conjugate | Proprietary polymer conjugatedwith Vitamin B12 and anisoluminol derivative,in MES buffer | Porcine intrinsic factor-alkalinephosphate (bovine) conjugatein TRIS buffered saline |
| AnalyticalMeasuring Range | 55 - 1500 pg/mL | 50 -1500 pg/mL |
| Calibrators | 2 Levels, on board | 5 Levels |
11. Standard/guidance Document Reference:
- CLSI Guideline EP5-A3, Evaluation of Precision of Quantitative Measurement o Procedures; Approved Guideline.
- CLSI Guideline EP15-A3, User Verification of Precision and Estimation of Bias; O Approved Guideline.
- CLSI Guideline EP EP07-A2, Interference Testing in Clinical Chemistry, O Approved Guideline.
- CLSI Guideline EP06-A, Evaluation of the Linearity of Quantitative Measurement O Procedures: A Statistical Approach; Approved Guideline.
- CLSI Guideline EP 17-A2, Evaluation of Detection Capability for Clinical o Laboratory Measurement Procedures; Approved Guideline.
- CLSI Guideline EP09-A3, Measurement Procedure Comparison and Bias O Estimation Using Patient Samples; Approved Guideline.
- CLSI Guideline EP28-A3C, Defining, Establishing and Verifying Reference o Intervals in the Clinical Laboratory; Approved Guideline.
12. Performance Characteristics:
Method Comparison
A total of 155 samples spanning the assay range, were tested by the LIAISON® Vitamin B12 and by another commercially available method following CLSI EP09-A3, and yielded the following Passing & Bablok regression analysis:
LIAISON® Vitamin B12 = 0.97 (Reference Method) + 6.25; R = 0.985.
{6}------------------------------------------------
| Assay | N | Slope (95% CI) | Intercept (95% CI) | CorrelationCoefficient |
|---|---|---|---|---|
| Vitamin B12 | 155 | 0.97 (0.94-1.00) | 6.25 (-3.50-18.29) | 0.985 |
Image /page/6/Figure/2 description: The image is a scatter plot titled "Scatter Plot with Passing & Bablok Fit". The x-axis is labeled "B12 (pg/mL) - Comparator Assay", ranging from 0 to 1500. The y-axis is labeled "LIAISON® 12 (pg/mL) - AVERAGE", ranging from 0 to 1600. The plot shows a linear relationship between the two variables, with a blue line representing the Passing & Bablok fit (6.25 + 0.97x) and a gray line representing identity.
Sample Matrix Comparison
Forty eight (48) matched patient sets of serum, SST serum and lithium heparin plasma samples were tested to determine if these sample types provide equivalent results on the LIAISON® Vitamin B12 assay.
Sample Equivalence SST serum compared to Serum
| N = 48 | Bias | 95% CI |
|---|---|---|
| Constant | 8.21 | 2.14 to 16.56 |
| Proportional | 0.97 | 0.94 to 0.99 |
| R2 | 0.996 | N/A |
Sample Equivalence Lithium Heparin compared to Serum
| N = 48 | Bias | 95% CI |
|---|---|---|
| Constant | 14.78 | 1.09 to 29.87 |
| Proportional | 1.10 | 1.05 to 1.15 |
| R2 | 0.988 | N/A |
Reference Range
It is recommended that each laboratory establish its own range of expected values for the population taken into consideration.
| Observed Reference Ranges | ||
|---|---|---|
| Population (n=166) | Median | Observed Range2.5th to 97.5th Percentile |
| United States | 318.5 (pg/mL) | 107.2 pg/mL – 653.3 pg/mL |
{7}------------------------------------------------
Prospectively collected serum samples from 166 apparently healthy adults aged 21-59 who had been fasting for at least 8 hours were obtained. Apparently healthy status of the adults were determined by the Inclusion/Exclusion criteria listed below. Samples were collected, centrifuged and removed from cells within 2 hours. Once serum was removed from the cells, the sample was frozen immediately and stored at -70°C in order to maintain integrity. Samples were shipped frozen and kept frozen until tested.
To assess the expected reference range for the LIAISON® Vitamin B12 assay, a study was performed with serum samples from 166 apparently healthy adults aged 21 - 59 years of age from mixed ethnic backgrounds (30% Caucasian, 31% African Americans, 39% Hispanics) who were fasting for at least 8 hrs. Apparently healthy status was determined by subjects who had no history of anemias, Folic acid or B12 deficiency, IBD or suspected IBD, celiac disease, gastrointestinal malabsorption disorders, or eating disorders. No oral contraceptive use within 3 months, and no alcohol within 48 hrs of blood draw or excessive alcohol usage. No pregnant women or anyone taking B12 supplementation were included in the study population.
Based on the 95% Confidence Interval, the following values were established following CLSI guideline C28-A3.
Precision
One (1) lot of kit controls and six (6) serum samples spanning the range of the assay measuring range were tested twice per day in duplicate, over 20 operating days using one (1) reagent lot at DiaSorin Inc. The testing was performed according to CLSI EP5-A3.
| Mean | Intra-RunWithin One Lotand Site | Total WithinOne Lot andSite | |||
|---|---|---|---|---|---|
| Sample ID | (pg/mL) | SD | %CV | SD | %CV |
| Sample #1 (KC) | 642 | 21.56 | 3.4% | 42.99 | 6.7% |
| Sample #2 (KC) | 1262 | 48.79 | 3.9% | 86.28 | 6.8% |
| Sample #3 | 240 | 10.16 | 4.2% | 20.36 | 8.5% |
| Sample #4 | 417 | 21.85 | 5.2% | 39.76 | 9.5% |
| Sample #5 | 646 | 24.83 | 3.8% | 57.55 | 8.9% |
| Sample #6 | 773 | 29.36 | 3.8% | 60.12 | 7.8% |
| Sample #7 | 1039 | 39.87 | 3.8% | 103.87 | 10.0% |
| Sample #8 | 1093 | 47.96 | 4.4% | 93.89 | 8.6% |
Linearity
One (1) high sample of each specimen type (serum, lithium heparin plasma) containing endogenous and/or spiked Vitamin B12 above the measuring range of the assay at 1500 pg/mL was diluted and tested by the LIAISON® Vitamin B12 assav following CLSI EP6-A. The results for each sample were analyzed by regression of observed concentration versus expected concentration.
{8}------------------------------------------------
The resulting equations for each sample type are: Serum: Observed Vitamin B12 = 1.076x + 6.896; R = 0.998 SST Serum: Observed Vitamin B12 = 1.009x + 0.224; R = 0.999 Lithium Heparin plasma: Observed Vitamin B12 = 1.029x - 0.095; R = 0.996
Recovery Study
Five (5) high concentration (endogenous or spiked) serum samples and five (5) low concentration serum samples were analyzed neat. Recovery samples were then prepared by mixing defined ratios of the high and low samples and tested in replicates of five (5). The mean results of the five (5) replicates are provided in the table below.
| DefinedConcentration | Expected(pg/mL) | Observed(pg/mL) | %Recovery | |
|---|---|---|---|---|
| SampleHigh | 1484 | - | - | - |
| 2 H:1 L | 1129 | 1144 | 101% | |
| 1 H:1 L | 946 | 940 | 99% | |
| 1 H:2 L | 763 | 752 | 99% | |
| Low neat | 108 | - | - | - |
| SampleHigh | 1280 | - | - | - |
| 2 H:1 L | 974 | 946 | 97% | |
| 1 H:1 L | 816 | 773 | 95% | |
| 1 H:2 L | 658 | 633 | 96% | |
| Low neat | 352 | - | - | - |
| SampleHigh | 1112 | - | - | - |
| 2 H:1 L | 827 | 816 | 99% | |
| 1 H:1 L | 680 | 683 | 100% | |
| 1 H:2 L | 533 | 553 | 104% | |
| Low neat | 247 | - | - | - |
| SampleHigh | 1098 | - | - | - |
| 2 H:1 L | 794 | 775 | 98% | |
| 1 H:1 L | 637 | 641 | 101% | |
| 1 H:2 L | 480 | 499 | 104% | |
| Low neat | 176 | - | - | - |
| SampleHigh | 1184 | - | - | - |
| 2 H:1 L | 853 | 904 | 106% | |
| 1 H:1 L | 682 | 707 | 104% | |
| 1 H:2 L | 512 | 534 | 104% | |
| Low neat | 180 | - | - | - |
| MeanRecovery | 100% |
{9}------------------------------------------------
Analytical Specificity
Cross-Reactivity Studies
Controlled Studies of potentially cross-reacting substances were performed on the LIAISON® Vitamin B12 assay at the concentrations listed below. The testing was based on CLSI-EP7-A2.
| Cross-Reactant | SpikedConcentration | % Cross Reactivity |
|---|---|---|
| Dicyanocobinamide | 10,000 pg/mL | -0.19% |
The cross reactivity study for the LIAISON® Vitamin B12 was designed to evaluate potential interference from other closely analytes with similar structure.
Interference Studies
Controlled studies of potentially interfering substances performed in serum at two (2) levels (200 and 800 pq/mL) demonstrated no interference in the LIAISON® Vitamin B12 at the highest concentration for each substance listed below.
| Drug/Substance | Concentration Tested |
|---|---|
| Hemoglobin | 300 mg/dL |
| Bilirubin (conjugated) | 40 mg/dL |
| Bilirubin (unconjugated) | 40 mg/dL |
| Triglycerides | 3,000 mg/dL |
| Cholesterol | 500 mg/dL |
| Albumin | 12 g/dL |
| Human IgG | 12 g/dL |
| HAMA | 1387.5 ng/mL |
| Rheumatoid Factor | 1035 IU/mL |
| Acetaminophen | 20 mg/dL |
| Acetylsalicylic Acid | 65 mg/dL |
| Ibuprofen | 50 mg/dL |
| Biotin | 2 mg/mL |
Limit of Blank, Limit of Detection and Limit of Quantitation
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined according to CLSI EP17-A2: Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures; Approved Guideline June 2012- Second Edition.
The following limits were determined with the LIAISON® Vitamin B12 assay: The limits are reported in the following table:
| LoB | LoD | LoQ |
|---|---|---|
| ≤ 38.7 pg/mL | 51.2 pg/mL | 55 pg/mL |
{10}------------------------------------------------
Stability
| Product | Storage Conditions | Claimed stability |
|---|---|---|
| Reagent Integral | Open vial on system | 42 days |
| Reagent Integral | Open vial 2-8°C | 28 days |
| Calibration curve | N/A | 21 days |
Traceability
The LIAISON® Vitamin B12 Calibrators are traceable to an in-house standard preparation (pg/mL).
13. Conclusion:
The LIAISON® Vitamin B12 assay is substantially equivalent in principle and performance to the Beckman Coulter Access Vitamin B12 assay.
§ 862.1810 Vitamin B
12 test system.(a)
Identification. A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of anemias of gastrointestinal malabsorption.(b)
Classification. Class II.