XN CAL is used for the calibration and calibration verification of Sysmex XN series (XN-10, XN-11, XN-20, XN-21, XN-L) analyzers. Assayed parameters include: WBC (10³/μL), RBC (10⁶/μL), HGB (g/dL), HCT (%), PLT (10³/μL), and RET (%).
Device Story
XN CAL is an in-vitro diagnostic calibrator consisting of stabilized red blood cells, white blood cells, platelets, and nucleated red blood cells in a preservative medium. It serves as a substitute for fresh whole blood to calibrate and verify hematology parameters (WBC, RBC, HGB, HCT, PLT, RET) on Sysmex XN-series analyzers. The product is packaged in polypropylene vials and stored at 2–8°C. It is used by laboratory personnel in clinical settings to ensure analyzer accuracy. The device output is a set of assayed values provided on a lot-specific sheet, which the healthcare provider uses to adjust or verify the performance of the hematology analyzer, ensuring reliable patient blood count results.
Clinical Evidence
No clinical data. Bench testing only. Multi-site reproducibility study (3 sites, 3 analyzers, 3 lots) and internal precision study (21 days) evaluated parameter recovery and variability (SD and %CV). Stability studies (open-vial 4-hour; closed-vial 35-day) confirmed performance per CLSI EP25-A guidelines.
Technological Characteristics
Stabilized blood components (RBC, WBC, PLT, nucleated RBC) in preservative medium. Polypropylene vials. Traceable to CLSI H7-A3, H15-A3, H26-A2, and ICSH reference methods. No electronic or software components; purely chemical/biological calibrator.
Indications for Use
Indicated for calibration and calibration verification of Sysmex XN series hematology analyzers (XN-10, XN-11, XN-20, XN-21, XN-L). For prescription use only.
Regulatory Classification
Identification
A calibrator for cell indices is a device that approximates whole blood or certain blood cells and that is used to set an instrument intended to measure mean cell volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC), or other cell indices. It is a suspension of particles or cells whose size, shape, concentration, and other characteristics have been precisely and accurately determined.
Special Controls
*Classification.* Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
A. 510(k) Number:
K160585
B. Purpose for Submission:
To expand the intended use of an existing cleared calibrator (XN CAL; K141962) for use on an additional analyzer, the Sysmex XN-L Analyzer. The XN CAL has previously been cleared for use on other Sysmex XN Series analyzers – the XN-10, XN-11, XN-20, and XN-21 analyzers.
C. Measurand:
Assayed hematology parameters: WBC (10³/μL), RBC (10⁶/μL), HGB (g/dL), HCT (%), PLT (10³/μL), and RET (%)
D. Type of Test:
Quantitative
E. Applicant:
Streck, Inc.
F. Proprietary and Established Names:
XN CAL
G. Regulatory Information:
1. Regulation section:
21 CFR § 864.8150, Calibrator for cell indices
2. Classification:
Class II
3. Product code:
KRX, Calibrator for cell indices
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4. Panel:
Hematology (81)
H. Intended Use:
1. Intended use(s):
XN CAL is used for the calibration and calibration verification of Sysmex XN series (XN-10, XN-11, XN-20, XN-21, XN-L) analyzers. Assayed parameters include: WBC (10³/μL), RBC (10⁶/μL), HGB (g/dL), HCT (%), PLT (10³/μL), and RET (%).
2. Indication(s) for use:
Same as intended use
3. Special conditions for use statement(s):
For prescription use only
4. Special instrument requirements:
Sysmex XN series (XN-10, XN-11, XN-20, XN-21, XN-L) analyzers
I. Device Description:
XN CAL is an in-vitro diagnostic product that contains the following: stabilized red blood cell component(s), stabilized white blood cell component(s), stabilized platelet component(s), and stabilized nucleated red blood cell component(s) in a preservative medium. The product is packaged in polypropylene plastic vials with screw caps. The vials will be packaged in five-welled or one-welled vacuum formed clamshell container with the Instructions for Use (IFU) assay sheet. The product must be stored at 2 – 8°C.
J. Substantial Equivalence Information:
1. Predicate device name(s):
XN CAL
2. Predicate 510(k) number(s):
K141962
3. Comparison with predicate:
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| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended Use | XN CAL is used for the calibration and calibration verification of Sysmex XN series hematology analyzers. Assayed parameters include: WBC (103/μL), RBC (106/μL), HGB (g/dL), HCT (%), PLT (103/μL), and RET (%). | Same |
| Reagents | XN CAL contains the following: stabilized red blood cell component(s), stabilized white blood cell component(s), stabilized platelet component(s), and stabilized nucleated red blood cell component(s) in a preservative medium. | Same |
| Storage Conditions | 2–8°C | Same |
| Open Vial Stability | 4 hours | Same |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended Use | XN CAL is used for the calibration and calibration verification of the following Sysmex XN series hematology analyzers: XN-10, XN-11, XN-20, XN-21, and XN-L. | XN CAL predicate is NOT cleared for calibration and calibration verification of XN-L analyzers. |
| Closed Vial Stability | 35 days | 49 days |
# K. Standard/Guidance Document Referenced (if applicable):
CLSI H7-A3: Procedure of Determining Packed Cell Volume by the Microhematocrit Method; Approved Standard - Third Edition.
CLSI H15-A3: Reference and Selected Procedures for the Quantitative Determination of Hemoglobin in Blood; Approved Standard - Third Edition.
CLSI H26-A2: Validation, Verification, and Quality Assurance of Automated Hematology Analyzers; Approved Standard - Second Edition
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CLSI EP05-A3: Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline – Third Edition.
## L. Test Principle:
XN CAL was designed to function as a substitute for fresh whole blood to calibrate the Sysmex XN10/20, XN 11/21, and XN-L series hematology analyzers. This product is for in-vitro diagnostic use to calibrate the following parameters: RBC (10⁶/μL), HGB (g/dL), HCT (%), PLT (10³/μL), WBC (10³/μL), and RET (%).
## M. Performance Characteristics (if/when applicable):
### 1. Analytical performance:
#### a. Precision/Reproducibility:
i. Multi-site reproducibility study: Data was collected from Sysmex XN-L model analyzers at three sites – Streck, Sysmex-Buffalo Grove, and Sysmex-Mundelein with three different operators. Three separately manufactured lots of XN CAL were tested on each analyzer. The study was conducted over the course of 5 days, with three runs per day, and two replicates per run (5 days x 3 runs x 2 replicates x 3 lots x 3 sites). The means for each of the assayed parameters for each lot are indicated in Table 1, below. The total reproducibility estimates (Table 2, below) for each parameter for each lot include the repeatability (within-run), between-run, between-day, and between-site precision estimates. Results across the three separately manufactured lots of XN CAL demonstrated consistent recovery across multiple instruments, at multiple sites.
| Table 1: Performance of XN CAL On Three XN-L Analyzers (3 sites) – Mean Values | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | Parameter Mean | | | | | |
| Lot | N | WBC | RBC | HGB | HCT | PLT | RET |
| Lot 6144* | 90 | 7.26 | 4.36 | 12.9 | 36.7 | 243 | 2.23 |
| Lot 6172* | 90 | 7.23 | 4.36 | 12.3 | 34.9 | 246 | 2.26 |
| Lot 6200* | 90 | 7.32 | 4.40 | 12.5 | 35.4 | 245 | 2.20 |
* = Within lot
| Table 2: Performance of XN CAL On Three XN-L Analyzers (3 sites) – Variability Estimates | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | Reproducibility Estimates for Each Parameter | | | | | | | | | | |
| Lot | WBC | | RBC | | HGB | | HCT | | PLT | | RET |
| | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD |
| Lot 6144* | 0.16 | 2.2 | 0.06 | 1.3 | 0.1 | 1.1 | 0.9 | 2.3 | 8 | 3.1 | 0.13 |
| Lot 6172* | 0.21 | 2.9 | 0.05 | 1.2 | 0.1 | 1.2 | 0.7 | 2.1 | 10 | 4.1 | 0.17 |
| Lot 6200* | 0.18 | 2.4 | 0.05 | 1.2 | 0.1 | 1.1 | 0.8 | 2.3 | 12 | 4.7 | 0.15 |
* = Within lot
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ii. Internal precision study: Performance data provided by the closed-vial stability study was used to support the internal precision study. In this study, performance of three (3) lots of XN CAL was evaluated at one site, on one instrument, for 21 non-consecutive days, two vials per day, and two replicates per vial. The internal precision for each lot of XN CAL was consistent across lots for each assayed parameter (see Tables 3 and 4, below). Total variability estimates (within-lab precision) included repeatability (within-run), between-vial, and between-day (Table 4, below).
| Table 3: XN CAL Internal Precision Study – Mean Values | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | Parameter Mean | | | | | |
| Lot | N | WBC | RBC | HGB | HCT | PLT | RET |
| Lot 5201* | 80 | 7.28 | 4.40 | 11.7 | 34.5 | 237 | 2.48 |
| Lot 5229* | 80 | 7.18 | 4.44 | 12.0 | 35.4 | 236 | 2.31 |
| Lot 5257* | 80 | 7.33 | 4.38 | 12.1 | 35.4 | 232 | 2.27 |
* = Within lot
| Table 4: Within Lab Precision for XN CAL | | | | | | | | | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | Total variability (within-lab precision) for Each Parameter | | | | | | | | | | | |
| Lot | WBC | | RBC | | HGB | | HCT | | PLT | | RET | |
| | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| Lot 5201* | 0.12 | 1.7 | 0.03 | 0.6 | 0.1 | 0.6 | 0.3 | 0.8 | 4 | 1.9 | 0.08 | 3.3 |
| Lot 5229* | 0.11 | 1.6 | 0.03 | 0.8 | 0.1 | 0.6 | 0.4 | 1.0 | 5 | 2.3 | 0.07 | 3.2 |
| Lot 5257* | 0.12 | 1.6 | 0.03 | 0.8 | 0.1 | 0.6 | 0.3 | 0.7 | 5 | 2.0 | 0.07 | 3.3 |
| Between Lots | 0.08 | 1.1 | 0.03 | 0.8 | 0.2 | 1.8 | 0.5 | 1.5 | 3 | 1.2 | 0.11 | 4.7 |
* = Within lot
b. Linearity/assay reportable range:
Not applicable
c. Traceability, Stability, Expected values (controls, calibrators, or methods):
**Value Assignment:**
Value assignment for the three lots of XN CAL evaluated in this submission was based on data collected across three XN-L instruments at three sites. Data was collected across three separately manufactured lots over the course of 5 non-consecutive days, with three (3) runs per day, and two (2) replicates per run. All assay ranges assigned to each lot for each of the parameters are based on the total reproducibility estimated from the multi-site reproducibility study. Assay values were assigned to the following parameters: RBC (10⁶/μL), HGB (g/dL), HCT (%), PLT (10³/μL), WBC (10³/μL), and RET (%). Future lots of XN CAL will be value assigned at one site by a minimum of one operator. Five repeat measurements will be taken from two separate vials of calibrator and assayed in a single run on each of the 2 days. The average of the 20 individual measurements will be used for value assignment. All lot specific assay values will be included on the lot specific assay
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sheet for each manufactured lot of control. This assay sheet will be included in each product package. Instruments at Streck are whole blood calibrated as per CLSI H26-A2 and the individual parameters are traceable to reference methods found in CLSI H7-A3, CLSI H15-A3, and ICSH Expert Panel on Cytometry publications (Clin. Lab. Haemat. 1998. v10, 203-212; and Am. J. Clin. Pathol. 2001. v115, 460-464).
## Traceability:
The instruments maintained at Streck and used for value assignment for XN CAL measurands were calibrated with whole blood in accordance with CLSI H26-A2 “Validation, Verification, and Quality Assurance of Automated Hematology Analyzers; Approved Standard – Second Edition,” and are traceable to the following reference methods:
- WBC and RBC: Reference method for the enumeration of erythrocytes and leucocytes, ICSH Expert Panel on Cytometry, Clin Lab Haematol. 1994; 16, 131-138. Counts are performed on SCC (Semi-automated Single Channel counter), a volumetric manometer semi-automated electronic impedance cell counter.
- HGB: Recommendation for reference method for haemoglobinometry in human blood (ICSH standard 1995) and specification for international haemiglobincyanide standard (4th edition), ICSH Expert Panel on Haemoglobinometry, J Clin Pathol 1996; 49: 271-274.
- HCT: Recommendations for Reference Method for the Packed Cell Volume (ICSH Standard 2001), ICSH Expert Panel on Cytometry, Clin Lab Hematol. 2001; 7:148-170.
- PLT: Platelet count values are determined by using a Neubauer Improved hemacytometer counting chamber and the bioanalytic® GmbH Thrombo-tic® PLT counting kit. This method is based on the procedure developed by Brecher and Cronkite.
- RET%: Methods for Reticulocyte Counting (Automated Blood Cell Counters, Flow Cytometry, and Supravital Dyes); Approved Guideline – Second Edition Manual method CLSI H44-A2.
- CLSI Document H15-A3, Reference and Selected Procedures for the Quantitative Determination of Hemoglobin in Blood, December, 2000.
## Reagent Stability:
i. Open-vial stability: A 4-hour real-time open-vial stability study was conducted at one site on the XN-L model analyzer. Throughout the collection of the open-vial stability data, the calibrator was stored as indicated in the instructions for use. Each vial was stored at $2 - 8^{\circ}\mathrm{C}$ and removed for testing. After testing, the vial was returned to $2 - 8^{\circ}\mathrm{C}$ until the next testing event. One vial of calibrator from each of the three lots was analyzed in four replicates on one day over a period of 5 hours (times 0, 2, 4, and 5 hours; $n = 16$ measurements), on one analyzer. Stability performance of each lot of calibrator was assessed in terms of
6
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parameter drift over time (for each parameter), as described in CLSI EP25-A – “Evaluation of Stability of In Vitro Diagnostic Agents; Approved Guideline.” Values associated with each parameter, for each lot, and at each time point were within the acceptable value range, supportive of a 4-hour open vial stability claim.
ii. Closed-vial stability: A real-time, 35-day closed-vial study was conducted internally on one Sysmex XN-L model analyzer by one operator. Two vials of calibrators from each of the three lots were analyzed in duplicate over the course of 38–39 days (with data collected every 4 days), providing measurements for 21 non-consecutive days. Stability performance of each lot of calibrator was assessed in terms of parameter drift over time (for each parameter), as described in CLSI EP25-A – “Evaluation of Stability of In Vitro Diagnostic Agents; Approved Guideline.” Values associated with each parameter, for each lot, and at each time point were within the acceptable value range, supportive of a 35-day closed-vial stability claim.
d. Detection limit:
Not applicable
e. Analytical specificity:
Not applicable
f. Assay cut-off:
Not applicable
2. Comparison studies:
a. Method comparison with predicate device:
Not applicable
b. Matrix comparison:
Not applicable
3. Clinical studies:
a. Clinical Sensitivity:
Not applicable
b. Clinical specificity:
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Not applicable
c. Other clinical supportive data (when a. and b. are not applicable):
Not applicable
4. Clinical cut-off:
Not applicable
5. Expected values/Reference range:
All lot specific assay values will be included on the lot specific assay sheet for each manufactured lot of calibrators. This assay sheet will be included in each product package.
N. Proposed Labeling:
The provided labeling is sufficient and satisfies the requirements of 21 CFR Part 809.10.
O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
8
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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.
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.