The FOB One Step Rapid Test is a rapid chromatographic immunoassay for the qualitative detection of human occult blood in human fecal specimens. The device is suitable for use in laboratories and physician's offices as well as for home use.
Device Story
FOB One Step Rapid Test is a lateral flow chromatographic immunoassay; utilizes double antibody-sandwich technique. Input: human fecal specimen. Principle: specimen reacts with anti-hemoglobin antibody-coated particles; mixture migrates via capillary action across membrane pre-coated with anti-hemoglobin antibody. Output: colored line in test region indicates positive result (presence of human hemoglobin); colored line in control region confirms proper wicking/volume. Used in laboratories, physician offices, and home settings; operated by technicians or lay users. Healthcare providers interpret visual lines to aid diagnosis of gastrointestinal disorders. Benefits patient by providing rapid, qualitative screening for occult blood.
Clinical Evidence
Bench testing only. Sensitivity/cutoff established at 50 ng hHb/mL. Reproducibility evaluated via inter-site, intra-run, and inter-day studies using spiked fecal samples (0-2000 ng/mL) across 3 lots; results showed consistent performance. Accuracy study compared device against predicate using 100 samples (technical personnel) and 150 samples (lay users). Technical personnel agreement: 99.0% with expected results, 98.0% with predicate. Lay user agreement: 98.7% with expected results, 98.0% with predicate. Cross-reactivity testing showed no interference from animal hemoglobins (beef, chicken, fish, horse, goat, pig, rabbit, sheep) at 200 ng/mL.
Technological Characteristics
Lateral flow chromatographic immunoassay; double antibody-sandwich technique. Employs colloidal gold particles. Dimensions/form factor: test cassette. Storage: 2-30°C. No electronic components, software, or external energy source required. Manual operation.
Indications for Use
Indicated for qualitative detection of human occult blood in fecal specimens to aid in diagnosis of gastrointestinal disorders. Suitable for use by healthcare professionals in laboratories and physician offices, and for over-the-counter (OTC) use by lay persons.
Regulatory Classification
Identification
An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)
Special Controls
*Classification.* Class II (special controls). A control intended for use with an occult blood test is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.
Predicate Devices
INSTANT-VIEW® Fecal Occult Blood Rapid Test (k070660)
Submission Summary (Full Text)
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
A. 510(k) Number:
k110309
B. Purpose for Submission:
New device
C. Measurand:
Human hemoglobin (hHb) in human feces
D. Type of Test:
Qualitative
E. Applicant:
Orient Gene Biotech
F. Proprietary and Established Names:
FOB One Step Rapid Test
G. Regulatory Information:
1. Regulation section:
21 CFR 864.6550, Occult blood test
2. Classification:
Class II
3. Product code:
KHE, Reagent, Occult blood
4. Panel:
Hematology (81)
H. Intended Use:
1. Intended use(s):
The FOB One Step Rapid Test is a rapid chromatographic immunoassay for the qualitative detection of human occult blood in human fecal specimens as an aid in the diagnosis of gastrointestinal disorders. The device is suitable for use in laboratories and physician’s offices as well as for over-the-counter use.
2. Indication(s) for use:
Same as intended use
3. Special conditions for use statement(s):
Prescription and over-the-counter use
4. Special instrument requirements:
Not applicable
I. Device Description:
The FOB One Step Rapid Test device consists of a sample well and a testing pad that employs double antibody-sandwich chromatographic immunoassay technology to detect the presence of FOB in human feces. The sample is collected in a tube containing collection buffer fluid.
J. Substantial Equivalence Information:
1. Predicate device name(s):
INSTANT-VIEW® Fecal Occult Blood Rapid Test
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2. Predicate 510(k) number(s): k070660
3. Comparison with predicate:
| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended use | Qualitative detection of occult blood in feces | Same |
| Sample Type | Feces | Same |
| Assay | Lateral flow chromatographic immunoassay | Same |
| Detection Level | 50 ng/mL hHb in fecal extraction buffer | Same |
| Users | Healthcare professionals and lay persons (OTC) | Healthcare professional use and lay persons (OTC) |
| Differences | | |
| Item | Device | Predicate |
| Format | Cassette only | Dip Strip and Cassette |
# K. Standard/Guidance Document Referenced:
None
# L. Test Principle:
The FOB One Step Rapid Test is a rapid qualitative test detecting the presence of human hemoglobin (hHb) in a fecal sample at $50\mathrm{ng / mL}$ and above. The tube is shaken to mix the fecal sample in the extraction buffer. Then, 3 drops (about $75\mu \mathrm{L}$ ) of the mixed sample solution is added onto the sample well of the test device. After the sample has been dispensed into the sample well, the extracted sample migrates into the pad containing detector antibody conjugated dye label. The hHb in the sample will bind to the detector antibody and migrate onto the membrane where the test and control lines are located. On the membrane, immobilized capture antibodies form the invisible Test line. When the complex of hHb and detector antibodies reaches the Test line, the complex binds to the capture antibodies to form a visible red Test line indicative of a positive result; i.e., hHb is present. When no hHb is present in the sample, no red Test line forms. In addition to the Test line, a Control line on the membrane provides an internal quality control of the test device. Anti-species specific IgG antibodies are immobilized at the Control line. These antibodies will capture any unreacted/excess antibody-gold conjugates, forming a distinct red Control line. The Control line serves to demonstrate that: lyophilized antibodies in the dye pad have been hydrated; sufficient sample has been applied to allow for migration to the Test line and beyond; chemicals are working properly; and the proper procedure was followed. If a Control line does not appear within the designated incubation time, the test result is invalid and the test should be repeated using a new test device.
# M. Performance Characteristics:
1. Analytical performance:
a. Precision/Reproducibility:
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Human stool samples in collection buffer were spiked with hHb at the following concentrations: 0, 37.5, 50, 62.5, and 2000 ng/mL. In the intra-run, intra-day precision studies, 10 samples were tested at each concentration with 3 lots of the FOB One Step Rapid Test. In the inter-site reproducibility studies, 15 samples were tested at each concentration with 3 lots of the FOB One Step Rapid Test. All samples with concentrations below 50 ng/mL hHb tested negative with the candidate device while samples at and above 50 ng/mL tested positive, as expected.
b. Linearity/assay reportable range
Not applicable
c. Traceability, Stability, Expected values (controls, calibrators, or methods):
Internal Control: Procedural controls are included in the test device. A red line appearing the control region is considered as the internal procedural control. It confirms sufficient specimen volume, adequate membrane wicking and correct procedural technique.
External Control: Controls are not provided with this kit. It is recommended that positive and negative controls be performed to verify proper test performance.
Stability of the Assay
Real time stability of the device (cassette and collection buffer solution vial) was tested with 3 lots of the device. Devices were stored at 20 - 30°C for 20 months. Nine devices from each lot were tested at 0, 3, 6, 9, 12, 15, 18 and 20 months. All test devices showed positive results when tested with an external positive control and showed negative results when tested with hemoglobin negative aqueous fecal samples. The expiration date of this device is set at 20 months when stored between 20°C - 30°C.
Sample Stability: Samples were stored in a refrigerator at 2- 8°C and tested with 10 cassettes at 0, 12, 24, 48 and 72 hours. Two concentrations of hHb - 12.5 ng/mL and 62.5 ng/mL- spiked into aqueous stool samples were tested. Based on these studies, the sample stability is determined to be 72 hours when stored between 2- 8°C.
Temperature Stress Study: Five test devices were tested after storing them in 4°C, 10°C, 25°C, 30°C, 37°C, 45°C, 50°C, 55°C and 60°C for 4 hours. Five test devices tested with hemoglobin concentration of 10 ng Hb/mL tested negative for the storage temperature limit of 50°C. The results for storage temperature above 50°C were invalid. Five test devices tested with hemoglobin concentration of 50 ng Hb/mL tested positive for the storage temperature limit of 50°C. The results for storage temperature above 50°C were invalid. The test device (cassette and buffer) showed acceptable performance after being stored for 4 hours in temperatures ranging from 4°C to 50°C.
d. Detection limit:
The detection limit of the device was determined by spiking 100 hemoglobin-free stool samples with varying concentrations (0, 37.5, 50, 62.5 and 2000 ng hHb/ml) of human hemoglobin. The test showed a cut-of 50 ng hHb/mL and no prozone effect was seen up to 2000 ng hHb/mL.
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The minimal detection limit of the device is 50 ng/mL of hHb in collection buffer.
e. Analytical specificity:
Positive and negative stool samples were spiked with the following substances: horseradish peroxidase (20 mg/mL), extract of red radish, extract of raw turnip, extract of cauliflower, extract of broccoli, dietary supplements with chlorine, fluoride, and iron, dietary supplements with Vitamin C and toilet water with and without cleaner and deodorizer. Animal hemoglobin from beef, chicken, fish, horse, goat, pig, rabbit, and sheep was also used in these studies. Addition of these substances had no effect on the test results.
g. Assay cut-off:
The assay cut-off is 50 ng/mL of hHb in buffer.
2. Comparison studies:
a. Method comparison with predicate device:
The FOB One Step Rapid Test was evaluated in comparison with a commercially available predicate device in foreign as well as US sites.
The foreign sites consisted of 3 physician office sites (POL) and 1 reference laboratory site. In the POL study, five different sample concentrations (0, 37.5, 50, 62.5, and 500 ng hHb/mL) were tested using the FOB One Step Rapid Test device and the predicate device using 20 replicates for each concentration, for a total of 100 samples. All samples were blind labeled. Results obtained from 3 sites agreed 99.0% with the expected results and 98.0% with the results obtained with the predicate device. In the reference laboratory site study (study of non-technical personnel), 30 participants tested 5 samples (1 at each concentration) with the two FOB devices. A total of 150 samples were tested in this study. There was 98.7% agreement with the expected results and 98.0% agreement with the results obtained with the predicate device.
The US study was a lay-user study conducted in two POL sites and one scientific laboratory site. Twenty lay-users per site participated in these studies by using their own specimens. The overall agreement of the test device with the predicate device when tested by lay-users was 95.0% (95% CI: 91% -100%). The overall agreement between the results obtained by lay-users and professional users was 98.3% (95% CI: 91% - 100%). In the study using spiked samples (12 per concentration), the overall agreement with the predicate device was 93.3% (95% CI: 84% - 97%).
b. Matrix comparison:
Not applicable
3. Clinical studies:
a. Clinical Sensitivity:
Not applicable
b. Clinical specificity:
Not applicable
c. Other clinical supportive data (when a. and b. are not applicable):
Not applicable
4. Clinical cut-off:
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Not applicable
5. Expected values/Reference range:
Results are negative when <50 ng/mL of hHb in collection buffer solution and positive when ≥ 50 ng/mL of hHb in collection buffer solution are present.
N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
O. Conclusion:
The submitted information in this premarket notification is complete and supports substantial equivalence decision.
5
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
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.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
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?
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.
Where do you find a device's intended use without opening the PDF?
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.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
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.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
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.
8. Chart view
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.
