VITROS Chemistry Products TRFRN Reagent is used to quantitatively measure transferrin (TRFRN) concentration in human serum and plasma. VITROS Calibrator kit 20 is used to calibrate VITROS 5,1 FS Chemistry System for quantitative measurement of transferrin, C3, C4, IgA and IgM. VITROS Chemistry Products Protein Performance Verifiers I, II and III are assayed controls used to monitor the performance of transferrin, C3, C4, IgA and IgM Reagents on the FS 5,1 Chemistry Systems.
Device Story
VITROS Chemistry Products TRFRN Reagent is an immunoturbidimetric assay for quantitative measurement of transferrin in human serum and plasma; used on VITROS 5,1 FS Chemistry System. Reagents 1 and 2 (goat anti-sera to human transferrin) are mixed with patient samples; antibody/antigen complexes increase solution turbidity; turbidity measured spectrophotometrically at 340 nm. Concentration determined via stored calibration curve. System operated by laboratory personnel in clinical settings. Output provides quantitative transferrin levels to assist clinicians in diagnostic decision-making. Includes calibrators and assayed controls for performance monitoring.
Clinical Evidence
Bench testing only. Performance validated through correlation studies with the predicate device (n=not specified, r=0.986, slope=0.96, intercept=-0.24 mg/dL). Additional bench studies included precision, analytical sensitivity, specificity, and expected values.
Technological Characteristics
Immunoturbidimetric assay; liquid reagents (Reagent 1: polymer/buffer/salt; Reagent 2: goat anti-human transferrin). Spectrophotometric detection at 340 nm. Calibrators and controls derived from processed human serum. Traceable to IRMM/IFCC CRM 470. Designed for VITROS 5,1 FS Chemistry System. Standards: NCCLS EP5-A, EP7-A, EP9-A, C28.
Indications for Use
Indicated for the quantitative measurement of transferrin in human serum and plasma for diagnostic purposes. Used on VITROS 5,1 FS Chemistry Systems.
Regulatory Classification
Identification
A transferrin immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the transferrin (an iron-binding and transporting serum protein) in serum, plasma, and other body fluids. Measurement of transferrin levels aids in the diagnosis of malnutrition, acute inflammation, infection, and red blood cell disorders, such as iron deficiency anemia.
Predicate Devices
IMMAGE® Immunochemistry System TRF Transferrin Reagent (K963427)
VITROS Chemistry Products Performance Verifiers I and II (K041720)
Submission Summary (Full Text)
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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
A. 510(k) Number:
k042477
B. Purpose for Submission:
New device
C. Measurand:
Transferrin
D. Type of Test:
Quantitative, immunoturbidimetry
E. Applicant:
Ortho-Clinical Diagnostics, Inc.
F. Proprietary and Established Names:
VITROS Chemistry Products TRFRN Reagent
VITROS Chemistry Products Calibrator Kit 20
VITROS Chemistry Products Protein Performance Verifiers I, II and III
G. Regulatory Information:
1. Regulation section:
21 CFR 866.5880, Transferrin immunological test system
21 CFR § 862.1150, Calibrator
21 CFR § 862.1660, Quality control material (assayed and unassayed)
2. Classification:
Class II, Transferrin reagent and calibrator
Class I, Quality control material
3. Product Code:
DDG, Transferrin, antigen, antiserum, control
JIT, Calibrator, secondary
JJX, Single (specified) analyte controls (assayed and unassayed)
4. Panel:
Immunology (82)
H. Intended Use:
1. Intended Use
VITROS Chemistry Products TRFRN Reagent is used to quantitatively measure transferrin (TRFRN) concentration in human serum and plasma.
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VITROS Calibrator kit 20 is used to calibrate VITROS 5,1 FS Chemistry System for quantitative measurement of transferrin, C3, C4, IgA and IgM.
VITROS Chemistry Products Protein Performance Verifiers I, II and III are assayed controls used to monitor the performance of transferrin, C3, C4, IgA and IgM Reagents on the FS 5,1 Chemistry Systems.
2. Indication(s) for use:
Same as intended use.
3. Special condition for use statement(s):
The devices are for prescription use only.
4. Special instrument Requirements:
VITROS 5,1 FS Chemistry System (k031924).
I. Device Description:
The VITROS Chemistry Products TRFRN Reagent is a dual-chambered package containing ready to use liquid reagents, Reagents 1 and 2. Reagent 1 consists of preservative, polymer, buffers and inorganic salt whereas Reagent 2 consists of goat anti-sera to human transferrin, preservative, buffer and inorganic salt.
The VITROS Chemistry Products Calibrator kit 20 contains 5 levels of calibrators prepared from processed human serum supplemented with inorganic salts, buffers and preservatives.
Protein performance verifiers contain three levels of assayed controls (low, medium and high) prepared from processed human serum supplemented with inorganic salts buffers and preservatives are added. The transferrin concentrations are: 119 mg/dL (level I), 236 mg/dL (level II) and 478 mg/dL (level III).
J. Substantial Equivalence Information:
1. Predicate device name(s):
Beckman IMMAGE Transferrin Assay and VITROS Performance Verifiers I and II.
2. Predicate K number(s):
Beckman IMMAGE Transferrin (k963427) and VITROS Performance Verifiers (k041720)
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3. Comparison with predicate:
| DEVICE | PREDICATE |
| --- | --- |
| A. Similarities | |
| Intended Use. Used to quantitatively measure transferrin concentration in human serum and plasma.
Assay Format – Quantitative
Performance Verifiers – assayed controls for monitoring performance of transferrin, C3, C4, IgA, IgG and IgM reagents | Quantitative determination of transferrin in human serum
Same
Same |
| B. Differences | |
| Assay type – Immunoturbidimetric
Instrument - VITROS 5,1 FS Chemistry Systems
Sample Type – Serum and plasma
Reportable range – 80 – 750 mg/dL
Control levels – low, medium and high
Matrix of Performance Verifiers – human serum | Rate nephelometric
Beckman IMMAGE
Immunochemistry Systems
Serum
75 – 750 mg/dL
Low and high
Freeze-dried human serum |
K. Standard/Guidance Document Referenced (if applicable):
NCCLS Guide line EP5-A, EP7-A, EP9-A, C28.
L. Test Principle:
Samples, calibrators and controls are automatically diluted in saline and mixed with Reagent 1 containing a polymer. Addition of antisera specific for human transferrin (Reagent 2) produces antibody/antigen complexes. The antibody/antigen complexes increase solution turbidity which is proportional to transferrin concentration in the sample. The turbidity is measured spectrophotometrically at 340 nm. The transferrin concentration in each unknown sample is determined using the stored calibration curve and the measured absorbance of the sample.
M. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
Within-day and within laboratory precision – Three samples with different transferrin concentrations were assayed in duplicate in two runs on each of 23 days on the VITROS 5,1FS System. Testing was performed on two lots of TRFRN Reagent. One set of the five level calibrators was run once weekly and results were used to generate a calibration curve for determining results for that week. Results of the test samples were analyzed using NCCLS EP5-A Guideline. Within-day precision was determined using two runs per day with two replications per run and within-lab precision was determined using a single lot of reagent.
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| Transferrin reagent (mg/dL) | | | %CV (mean) | #observed | #days |
| --- | --- | --- | --- | --- | --- |
| Mean Conc | Within-Day (SD) | Within-Lab (SD) | | | |
| 138.08 | 0.952 | 6.354 | 4.6 | 91 | 23 |
| 269.88 | 1.463 | 7.077 | 2.6 | 92 | 23 |
| 547.07 | 6.542 | 24.491 | 4.5 | 92 | 23 |
b. Linearity/assay reportable range:
Linearity of the VITROS TRFRN Reagent assay was evaluated according to NCCLS EP6-A. The high pool was Level 5 of the VITROS Calibrator Kit 20 and had a transferrin concentration of 753 mg/dL and the low pool was Level 1 and had a transferrin concentration of 78.3 mg/dL. Thirteen levels spanning the assay reportable range were created by mixing the high and low pools. Three determinations of each of the 13 levels were made together with 3 determinations of the VITROS Performance Protein Verifiers. Linear regression analysis indicated that the assay is linear across the range tested (78.3 mg/dL to 753 mg/dL) with y = 6.8728x + 75.747 where x is dilution in % high pool. Correlation coefficient (r²) was 0.999. The product claim for linearity over the reportable range is 80 to 750 mg/dL.
Dilution Study - A total of 5 patient samples, one high calibrator and one concentrated patient pool at the high end of the assay range were evaluated. Recoveries were calculated based on undiluted values measured on the same samples run on the VITROS 5,1 FS Chemistry System. For out of range samples, recoveries were calculated from neat results predicted form an off-board calculation using the initial absorbance results. Recovery of each sample was determined as a % of the neat sample concentration. The two lots tested showed the mean % recovery value of 101% with individual sample recoveries ranged from 96.1% to 104.5% (acceptance criteria was set at 91%-109%). Results also showed that samples with values greater than the reportable range may be diluted up to 1 part sample with 1 part diluent (saline).
The assay reportable range is 80 to 750 mg/dL or 0.8 to 7.5 g/L.
c. Traceability (controls, calibrators, or method):
Values assigned to the Calibrator Kit 20 for transferrin are traceable to IRMM /IFCC (Institute for Reference Methods and Materials) CRM 470 (RPPHS, Reference Preparation for Proteins in Human Serum) reference material.
Calibrator value assignment for transferrin - a five level set of calibrators are prepared using the VITROS 5,1 FS Chemistry System
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on-analyzer dilution of CRM 470. These calibration standards are used to measure and assign values to a Master Lot of working calibrators as well as to calibrate the Manufacturer's Selected Measurement Procedure for the VITROS TRFRN Reagent. The Master Lot and the selected measurement procedure are then used to assign values to subsequent Calibrator Kit 20 production lots.
d. Detection limit (functional sensitivity):
Not provided.
e. Analytical specificity:
Endogenous and exogenous interfering substances were tested according to NCCLS EP7-A in samples with transferrin level of approximately 183 mg/dL (for bilirubin, hemoglobin and Intralipid, samples had approximately 134 mg/dL transferrin). For each interference substance, a control pool and a spiked-in-pool were analyzed in quadruplicate using three reagent lots.
Substances tested included: Acetominophen (200 µg/mL), acetyl-L-cystein (100 mg/dL), Amoxicillin (20 µg/mL), ascorbic acid (3 mg/dL), bilirubin (842.9 g/mol), carbamazepine (120 µg/mL), dipyrone (30 mg/dL). Ethamsylate (3 mg/dL), gentamicin sulfate (120 µg/mL), hemoglobin (13647 mg/dL), ibuprofen (400 µg/mL), methotrexate (2 mmol/L), procainamide (100 µg/mL), propranolol (5000 ng/mL), rantidine (200 µg/mL), lidocaine (60 µg/mL), simvastatin (16 µg/mL), theophylline (250 µg/mL), salicylic acid (500 µg/mL), intralipid (1000 mg/dL), triglycerides (1000 mg/dL) and valproic acid (500 µg/mL). No interference was observed at the concentrations tested.
f. Assay cut-off:
Not provided.
2. Comparison studies:
a. Method comparison with predicate device:
A total of 139 serum samples were assayed using VITROS Chemistry Products TRFRN assay and the Beckman IMMAGE Transferrin assay for comparison. All samples were analyzed in triplicate on the VITROS 5,1 FS Chemistry System analyzer and in singleton on the Beckman IMMAGE using two lots of reagents. Only samples within the reportable range of both devices were analyzed. Two samples were excluded because they were out of the reportable range for one of the devices. Data were screened for statistical outliers and no data were rejected. The mean of the triplicates from the VITROS Chemistry Products TRFRN assay and the single replicate for the Beckman IMMAGE Transferrin assay
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were compared by least squares linear regression analysis. Results showed (VITROS) = 0.96 x (IMMAGE) - 0.24 (mg/dL) with a correlation coefficient (r) of 0.986. The 95% confidence intervals (CI) for slope and intercept were 0.94 to 0.99 and -8.97 to 8.50 respectively.
b. Matrix comparison:
For the serum and plasma comparison study, blood from 6 subjects collected in different collection tubes (red top tubes, lithium heparin (Li heparin), EDTA, serum separator [SST], and plasma separator [PST]) as well as 60 paired serum/lithium plasma samples were analyzed. Serum and plasma were separated within 1 hour of collection. Data analysis was performed according to NCCLS EP5-A. Regression analysis of the 60 paired serum and Li heparin plasma samples yielded [Li heparin] = 1.0172 (Serum) -3.9218 with a correlation coefficient (r) of 0.9781. The results of the other tube tubes were within acceptable limits.
3. Clinical studies:
a. Clinical sensitivity: Not provided.
b. Clinical specificity: Not provided.
c. Other clinical supportive data (when a and b are not applicable): Not applicable.
4. Clinical cut-off: Not provided.
5. Expected values/Reference range:
The expected values for transferrin were determined by assaying 121 samples from apparently healthy subjects using two lots of reagents. The evaluation was performed using NCCLS C28 guideline. The reference interval for lot 1 was 207.7 to 389.4 mg/dL with a mean of 290.5 mg/dL and a median of 286.7 mg/dL. The 90% confidence intervals of the 2.5th and 97.5th percentile values were 198.5 to 224.9 mg/dL and 358.5 to 398.8 mg/dL respectively. The reference interval for lot 2 was 204.0 to 372.9 mg/dL with a mean of 283.9 mg/dL and a median of 282.6 mg/dL. The 90% confidence intervals of the 2.5th and 97.5th percentile values were 191.2 to 221.0 mg/dL and 352.7 to 397.3 mg/dL respectively. The overall reference interval based on the two lots was determined to be 206 to 381 mg/dL (2.1-3.8 SI Units [g/L]).
N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
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O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
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Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
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Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
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2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
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Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
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Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
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What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
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Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
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A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
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The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.