GradiLeiden V is a simple functional clotting test system intended for sceening of resistance to Activated Protein C in plasma from individuals with the Factor V (Leiden) defect. It can also be performed on plasma from patients on stabilized oral anticoagulant or heparin therapy.
Device Story
GradiLeiden V is an in vitro diagnostic clotting test used in clinical laboratories to screen for Factor V (Leiden) mutation. The device utilizes a lyophilized reagent containing Agkistrodon contortrix venom and Russell's Viper Venom to activate the patient's protein C pathway. Unlike predicate tests requiring plasma dilution, this test is insensitive to heparin, Lupus Anticoagulants, and factor deficiencies from oral anticoagulants. The test is performed on automated two-stage clotting systems (e.g., Stago STA, Dade Behring BCS, Organon Teknika MDA180) or via manual tilt tube technique. The system compares a blank test to a venom-activated test to calculate a ratio; a ratio below the established cut-off indicates potential Factor V (Leiden) mutation. Results assist clinicians in identifying patients with hereditary thrombophilia, enabling appropriate management of coagulation disorders.
Clinical Evidence
Clinical validation compared GradiLeiden V against the predicate device in a series of clotting assays, with results confirmed by DNA analysis. Study included 164 individuals (82 negative), 35/36 oral anticoagulated plasmas, 21/21 heparinized plasmas, and 12/12 Lupus Anticoagulant positive plasmas. Using a ROC-determined cut-off of 1.57, the device demonstrated 100% sensitivity and 98.8% specificity. Precision testing showed within-run precision of 0.9% at the cut-off and total precision ranging from 1.6% to 8.9% across different plasma types.
Technological Characteristics
In vitro diagnostic clotting test. Reagents: lyophilized Agkistrodon contortrix venom and phospholipid-rich Russell's Viper Venom. Principle: two-stage clotting assay measuring APC resistance via ratio calculation. Form factor: lyophilized vials for use in automated coagulation analyzers or manual tilt tube. Connectivity: standalone reagent system for use with standard laboratory coagulation instrumentation. No software algorithm class specified; relies on instrument-based clotting time acquisition.
Indications for Use
Indicated for screening individuals for Activated Protein C resistance associated with the Factor V (Leiden) defect. Suitable for use with plasma from patients on stabilized oral anticoagulant or heparin therapy.
Regulatory Classification
Identification
A partial thromboplastin time test is a device used for primary screening for coagulation abnormalities, for evaluation of the effect of therapy on procoagulant disorders, and as an assay for coagulation factor deficiencies of the intrinsic coagulation pathway.
Predicate Devices
Coatest APC Resistance V
Submission Summary (Full Text)
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## 510(k) Summary
## GradiLeiden V Test
## The submitter's name, address, telephone number, a contact person, and the date the (a)(1) summary was prepared;
Submitter's Name: Gradipore Ltd
Submitter's Address: Lot 16 Riverside Corporate Park 35 - 105 Delhi Rd, North Ryde 2113 Australia
Submitter's Telephone: 1800 762 2620
Submitter's Contact: Rhonda Pilgrim Regulatory Affairs Manager
Date 510(k) Summary Prepared: 21 July, 1999
### The name of the device, including the trade or proprietary name if applicable, the common (a)(2) or usual name, and the classification name, if known;
Trade or Proprietary Name: GradiLeiden V
Common or Usual Name: APC Resistance Test
Classification Name: Hematology
#### An identification of the legally marketed device to which the submitter claims substantial (a)(3) equivalence;
Device Equivalent to: Coatest APC Resistance V
#### A description of the device. (a)(4)
Device Description: The GradiLeiden V Test is a lyophilized paired reagent containing 5 vials of whole diluted Agkistrodon contortrix venom and 5 vials of phospholipid rich Russell's Viper Venom time reagent.
#### A statement of the intended use of the device. (a)(5)
## Device Intended Use:
Device Intended Use. OrialDoron - 15 a smillion with the Factor V (Leiden) defect. It can also be performed on plasma from patients on stabilized oral anticoagulant or heparin therapy.
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## GRADILEIDEN V 510(k) Submission July, 1999
#### A summary of the technological characteristics of the new device in comparison to (a)(6) those of the predicate device.
GradiLeiden V is a clotting test based on lyophilised Russell's Viper Venom, which activates clotting at Factor X in the common pathway, while the Coatest APC Resistance V test is a clotting test based on an APTT system. The Factor V Leiden mutation affects Factor V in the common pathway, so both clotting tests are equally sensitive to the defect.
GradiLeiden V uses a lyophilised snake venom to activate the patient's own protein C while the Coatest APC Resistance V test uses lyophilised purified activated protein C.
Both tests can be automated in 2 stage clotting test systems with similar activation and acquisition times.
GradiLeiden V does not require dilution of plasma samples as the test is insensitive to heparin, Lupus Anticoagulants and to factor deficiencies caused by oral anticoagulants. Coatest APC Resistance V test requires dilution of patient samples in Factor V depleted plasma in order to eliminate sensitivity to heparin, Lupus Anticoagulants and oral anticoagulants.
#### A brief discussion of the nonclinical tests submitted, referenced, or relied on in the (b)1) premarket notification submission for a determination of substantial equivalency.
GradiLeiden V and Coatest APC Resistance V test both have the same intended use and can be used with the same patient groups. Both tests are automatable two stage clotting tests, wherein a blank test and a test in which either APC (Coatest APC Resistance V) or Venom activator (GradiLeiden V) are compared and a ratio obtained. The normal range for this ratio in both tests is reported as approximately 2-3. While both tests can be used for patients on oral anticoagulant or heparin therapy and for Lupus Anticoagulant positive patients. GradiLeiden V does not require plasma dilution while the Coatest APC Resistance V does. Within run precision for both tests is less than 5%.
#### A brief discussion of the clinical tests submitted, referenced, or relied on in the premarket (b)(2) notification submission for a determination of substantial equivalency.
GradiLeiden V was compared against the predicate device in a series of clotting assays, with all results confirmed by DNA analysis. Using a cut-off of 1.57 obtained by ROC analysis, Gradil.eiden V correctly identified the Factor V Leiden status of 163/164 individuals (82 negative). These included 35/36 Oral Anticoagulated plasmas, 21/21 heparinised plasmas and 12/12 Lupus Anticoagulant positive plasmas. GradiLeiden V was tested using the Stago STA, Dade Behring BCS, Organon Teknika MDA180 and manual tilt tube technique. The test was found to have 100% sensitivity and 98.8% specificity at a cut-off of 1.57 determined by ROC analysis.
Total precision estimates for FVL+, borderline normal, and normal plasma are 8.9%, 1.6%, and 5.6%, respectively. Within run precision estimates for FVL+ and normal plasma are 1.1% and 1.9%. Within run precision at the cutoff is 0.9%
### (b)3) The conclusions drawn from the nonclinical and clinical tests that demonstrate that the device is as safe, as effective, and performed as well or better than the legally marketed device identified in (a)(3).
Gradipore Ltd considers GradiLeiden V to be substantially equivalent to the Chromogenix AB Coatest APC Resistance V Test in terms of intended use, method comparison and overall performance characteristics.
Image /page/1/Picture/13 description: The image shows the words "Gradipore ORIGINAL (if in red)" in a bold, sans-serif font. The words are stacked on top of each other, with "Gradipore" on the top line, "ORIGINAL" on the second line, and "(if in red)" on the third line. The text is black and the background is white. The text appears to be part of a label or document.
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## GRADILEIDEN V 510(k) Submission July, 1999
#### 17.0 QUALITY ASSURANCE/QUALITY CONTROL
The following is Gradipore Ltd's recommended quality control for the use of GradiLeiden V Test in clinical laboratories:
Each laboratory should establish its own normal range and abnormal range for each lot of GradiLeiden V Test reagent.
The use of control plasma is recommended for monitoring coagulation assays following established laboratory quality control procedures. NCCLS recommends controls be assayed at the initiation of testing, at least once each shift, or with each group of assays. In high volume laboratories, controls should be tested with at least every 40 samples, as per NCCLS tentative guidelines H28-T, 1992.
If control values are out of range, do not report patient results. Determine which part of the instrument/reagent/control system is not functioning properly and correct it. After corrective measures are implemented and documented following good laboratory practice, retest the controls. If they are within range, patient samples can be tested and reported.
Image /page/2/Picture/6 description: The image shows the words "Gradipore ORIGINAL (if in red)" stacked on top of each other. The word "Gradipore" is at the top, followed by the word "ORIGINAL" in a slightly larger font. The phrase "(if in red)" is at the bottom in a smaller font. The text appears to be slightly distressed or textured.
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Food and Drug Administration 2098 Gaither Road Rockville MD 20850
DEC 2 1 1999
Ms. Rhonda Pilgrim M.SC. Regulatory Affairs Manager Gradipore Ltd. Haemostasis Lot 16 Riverside Corporate Park 35 – 105 Delhi Road North Ryde 2113 Australia
Re: K992456 Trade Name: GradiLeiden V Test Regulatory Class: II Product Code: GGW Dated: November 10, 1999 Received: November 17, 1999
Dear Ms. Pilgrim:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we 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). You may, therefore, market the device, subject to the general controls provisions of the Act. 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.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (OS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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## Page 2
Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770) 488-7655.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".
Sincerely yours,
Steven Putman
Steven I. Gutman, M.D, M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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# GRADILEIDEN V 510(k) Sudmissium July, 1999
# 18.0 INTENDED USE STATEMENT
510(k) Number (If known): K992456
Device Name: GradiLeiden V Test
Indications For Use:
GradiLeiden V is a simple functional clotting test system intended for sceening of resistance to Gradil eiden V is a smillional cloiding cloridize with the Factor V (Leiden) defect. It can also be
Activated Protein C in plasma from individuals with the Factor V (Leidene Activated Protein C in plasma from marrialians was more anticoagulant or heparin therapy.
# (PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
| | <img alt="Signature" src="signature.png"/> |
|-----------------------------------------|--------------------------------------------|
| (Division Sign-Off) | |
| Division of Clinical Laboratory Devices | |
| 510(k) Number | K952456 |
| Prescription Use <img alt="Checkmark" src="checkmark.png"/> (Per 21 CFR 801.109) | OR | Over-The-Counter Use ______ |
|----------------------------------------------------------------------------------|----|-----------------------------|
| | | (Optional Format 1-2-96) |
Image /page/5/Picture/8 description: The image shows the words "Gradipore ORIGINAL (if in red)" stacked on top of each other. The words are in a bold, sans-serif font. The words are slightly distorted, as if they were printed on a textured surface. The words are all in black ink.
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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 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?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
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.
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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?
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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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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.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
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.