← Product Code [GIM](/submissions/CH/subpart-b%E2%80%94clinical-chemistry-test-systems/GIM) · K080552

# CYTO-CHEX BCT (K080552)

_Streck · GIM · Jul 31, 2008 · Clinical Chemistry · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/HE/subpart-b%E2%80%94clinical-chemistry-test-systems/GIM/K080552

## Device Facts

- **Applicant:** Streck
- **Product Code:** [GIM](/submissions/CH/subpart-b%E2%80%94clinical-chemistry-test-systems/GIM.md)
- **Decision Date:** Jul 31, 2008
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 862.1675
- **Device Class:** Class 2
- **Review Panel:** Clinical Chemistry

## Indications for Use

Cyto-Chex® BCT is intended for the collection and storage of blood specimens for immunophenotyping of WBC by flow-cytometry. Recovery of lymphocyte subset cell markers of the HIV panel can be accomplished over a 14-day period following collection.

## Device Story

Cyto-Chex® BCT is a 13x75mm glass vacuum blood collection tube containing K3EDTA and a WBC preservative; used for venipuncture collection of 5ml blood samples. Device preserves peripheral blood leukocyte subset characteristics for immunophenotyping via flow cytometry. By stabilizing samples for up to 14 days, it allows for delayed analysis of lymphocyte markers (CD3, CD4, CD8, CD16/56, CD19, CD45) compared to standard EDTA tubes. Used in clinical laboratory settings; processed by laboratory technicians. Output is a preserved blood sample suitable for flow cytometric analysis, enabling accurate monitoring of immunodeficiency and hematologic diseases without requiring immediate processing.

## Clinical Evidence

Clinical study compared peripheral blood samples from healthy donors and HIV-positive patients collected in Cyto-Chex BCT versus K3EDTA tubes. Samples analyzed over 14 days using Becton-Dickinson FACSCalibur and Beckman Coulter EPICS XL flow cytometers. Reference values established from K3EDTA samples at 6 hours. Results showed stability of CD3, CD4, and CD8 markers with correlation statistics (trendline slope >0.90, R-values >0.85).

## Technological Characteristics

13x75mm glass vacuum tube; contains 75.8ul K3EDTA anticoagulant and WBC preservative. Principle: chemical stabilization of cell-surface markers for flow cytometry. No electronic components, software, or energy source.

## Regulatory Identification

A blood specimen collection device is a device intended for medical purposes to collect and to handle blood specimens and to separate serum from nonserum (cellular) components prior to further testing. This generic type device may include blood collection tubes, vials, systems, serum separators, blood collection trays, or vacuum sample tubes.

## Predicate Devices

- Cyto-Chex® BCT ([K040107](/device/K040107.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
> Innolitics is a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices, including [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/).

{0}

1

510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
ASSAY ONLY TEMPLATE

A. 510(k) Number:
K080552

B. Purpose for Submission:
Change in volume of reagent in tube.

C. Measurand:
Leukocyte subsets

D. Type of Test:
Qualitative and Quantitative, Flow Cytometry

E. Applicant:
Streck Laboratories, Inc.

F. Proprietary and Established Names:
Cyto-Chex® BCT

G. Regulatory Information:
1. Regulation section:
21 CFR 862.1675
2. Classification:
Class II
3. Product code:
GIM
4. Panel:
75 Chemistry

{1}

H. Intended Use:

1. Intended use(s):

Cyto-Chex® BCT is intended for the collection and storage of blood specimens for immunophenotyping of WBC by flow-cytometry. Recovery of lymphocyte subset cell markers of the HIV panel can be accomplished over a 14-day period following collection.

2. Indication(s) for use:

Cyto-Chex® BCT is intended for the collection and storage of blood specimens for immunophenotyping of WBC by flow-cytometry. Recovery of lymphocyte subset cell markers of the HIV panel can be accomplished over a 14-day period following collection.

3. Special conditions for use statement(s):

Not applicable.

4. Special instrument requirements:

Not applicable.

I. Device Description:

Cyto-Chex® BCT consists of a standard 13 x 75mm glass blood collection tube containing 75.8 μl of sterile K₃EDTA anti-coagulant and WBC preservative. It is manufactured with a vacuum to draw 5 ml of blood by venipuncture.

J. Substantial Equivalence Information:

1. Predicate device name(s):

Cyto-Chex® BCT

2. Predicate K number(s):

K040107

{2}

3

3. Comparison with predicate:

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Cyto-Chex® BCT | Cyto-Chex® BCT(K040107)  |
|  Intended Use | For the collection and storage of blood specimens for immunophenotyping of WBC by flow-cytometry. | Same.  |
|  Tube type | Glass | Same  |
|  Tube size | 13 x75mm | Same  |
|  Contents | K_{3}EDTA and preservative | Same  |
|  Sample volume | 5 ml | Same  |
|  Differences  |   |   |
| --- | --- | --- |
|  Item | Cyto-Chex® BCT | Cyto-Chex® BCT (K040107)  |
|  Reagent Volume | 75.8 μl | 57 μl  |
|  Preservation of HIV markers | 14 days | 7 days  |

K. Standard/Guidance Document Referenced (if applicable):

NCCLS Standard H1-A4 Evacuated Tubes and Additives for Blood Specimen Collection, Fourth Addition; Approved Standard

L. Test Principle:

Subsets of leukocytes can be distinguished on the basis of cell surface antigens using fluorescent antibodies and flow cytometry. Qualitative and quantitative changes in leukocyte subsets are used to identify and monitor immunodeficiency and hematologic diseases. Cyto-Chex® BCT is designed to preserve peripheral blood samples qualitative and quantitative leukocyte subset characteristics.

M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Not applicable.

b. Linearity/assay reportable range:

Not applicable.

{3}

c. Traceability, Stability, Expected values (controls, calibrators, or methods):

Not applicable.

d. Detection limit:

Not applicable.

e. Analytical specificity:

A statement was added to the package insert that samples which are icteric, lipemic, or hemolyzed need to be noted on the laboratory report as suspect.

f. Assay cut-off:

Not applicable.

## 2. Comparison studies:

a. Method comparison with predicate device:

The following two studies were performed using two different flow cytometers:

The first study was to assess lymphocyte subset cell-surface markers obtained from peripheral blood by collecting samples from 16 healthy donors in EDTA and Cyto-Chex BCT tubes. Within 6 hours both tubes were analyzed on a flow cytometer. Samples collected in Cyto-Chex BCT were held at room temperature and also analyzed at 7 days, 11 days and 14 days. The following markers were used for the analysis: CD3, CD4, CD8, CD16/56 and CD19. Included in the collection data are Absolute cell counts values for each lymphocyte subset as well as the  $\%$  Recovery for each marker. All correlations were referenced to the EDTA tube at 6 hours.

Summary of Regression for healthy donors (Absolute Counts)

|  Marker | Time Interval | Slope | R2  |
| --- | --- | --- | --- |
|  CD3 | 6 hour | 0.96 | 0.9607  |
|   | 7 day | 1.04 | 0.9564  |
|   | 11 day | 0.96 | 0.9590  |
|   | 14 day | 0.97 | 0.9763  |
|  |   |   |   |
|  CD4 | 6 hour | 0.96 | 0.9795  |
|   | 7 day | 1.04 | 0.9478  |
|   | 11 day | 1.02 | 0.9600  |
|   | 14 day | 0.98 | 0.9727  |
|  |   |   |   |

{4}

|  CD8 | 6 hour | 0.95 | 0.9464  |
| --- | --- | --- | --- |
|   | 7 day | 1.00 | 0.9603  |
|   | 11 day | 0.94 | 0.9583  |
|   | 14 day | 0.95 | 0.9811  |
|  |   |   |   |
|  CD16/56 | 6 hour | 0.98 | 0.9758  |
|   | 7 day | 0.84 | 0.8432  |
|   | 11 day | 0.89 | 0.9468  |
|   | 14 day | 0.83 | 0.8735  |
|  |   |   |   |
|  CD19 | 6 hour | 0.98 | 0.9774  |
|   | 7 day | 0.95 | 0.9485  |
|   | 11 day | 0.94 | 0.9633  |
|   | 14 day | 0.93 | 0.9557  |

A second clinical study was to assess the stability of lymphocyte subsets in specimen samples by collecting samples from 10 HIV positive donors and 10 normal donors stored in Cyto-Chex BCT tubes. They were analyzed with the flow cytometer using single-platform methods at 6 hour, 7 days, 11 days and 14 days after collection. The following markers were used for the analysis: CD3, CD4, CD8, CD16/56, CD19 and CD45. The number of lymphocytes positive for the indicated marker was recorded for two runs at each time point. The results were averaged for each donor. Regression analysis was used for the relationship between the average measurement from each time point and the control (EDTA 6 hours). The results showed the estimate slopes are close to 1.0 and R2 values are all  $>0.97$  indicating a good agreement between the control and the Cyto-Chex BCT tubes.

Summary of Regression for HIV donors (Absolute Count)

|  Marker | Time Interval | Slope | 95% CI for Slope | R2  |
| --- | --- | --- | --- | --- |
|  CD3 | 6 hour | 1.03 | 0.99 to 1.06 | 0.9986  |
|   | 7 day | 1.04 | 1.01 to 1.07 | 0.9984  |
|   | 11 day | 0.99 | 0.93 to 1.04 | 0.9945  |
|   | 14 day | 1.06 | 0.99 to 1.12 | 0.9947  |
|  |   |   |   |   |
|  CD4 | 6 hour | 1.00 | 0.98 to 1.03 | 0.9987  |
|   | 7 day | 1.04 | 1.01 to 1.07 | 0.9981  |
|   | 11 day | 1.01 | 0.94 to 1.08 | 0.9908  |
|   | 14 day | 1.03 | 0.98 to 1.08 | 0.9959  |
|  |   |   |   |   |
|  CD8 | 6 hour | 1.03 | 1.00 to 1.06 | 0.9986  |
|   | 7 day | 1.02 | 0.99 to 1.06 | 0.9981  |
|   | 11 day | 0.96 | 0.91 to 1.01 | 0.9959  |
|   | 14 day | 1.04 | 0.97 to 1.11 | 0.9928  |
|  |   |   |   |   |
|  CD16/56 | 6 hour | 1.11 | 1.02 to 1.20 | 0.9894  |
|   | 7 day | 1.08 | 0.99 to 1.07 | 0.9987  |
|   | 11 day | 1.02 | 0.95 to 1.09 | 0.9914  |
|   | 14 day | 0.99 | 0.87 to 1.10 | 0.9781  |
|  |   |   |   |   |

{5}

|  CD19 | 6 hour | 1.02 | 0.97 to 1.06 | 0.9966  |
| --- | --- | --- | --- | --- |
|   | 7 day | 0.99 | 0.93 to 1.05 | 0.9939  |
|   | 11 day | 0.91 | 0.85 to 0.98 | 0.9911  |
|   | 14 day | 0.87 | 0.79 to 0.95 | 0.9855  |
|  |   |   |   |   |
|  CD45 | 6 hour | 1.04 | 0.98 to 1.10 | 0.9944  |
|   | 7 day | 1.06 | 1.01 to 1.11 | 0.9955  |
|   | 11 day | 1.01 | 0.95 to 1.06 | 0.9951  |
|   | 14 day | 1.02 | 0.96 to 1.09 | 0.9933  |

Summary of Regression for normal donors (Absolute Count)

|  Marker | Time Interval | Slope | 95% CI for Slope | R²  |
| --- | --- | --- | --- | --- |
|  CD3 | 6 hour | 0.97 | 0.94 to 1.01 | 0.9981  |
|   | 7 day | 1.02 | 0.98 to 1.06 | 0.9978  |
|   | 11 day | 1.03 | 0.99 to 1.07 | 0.9979  |
|   | 14 day | 1.01 | 0.96 to 1.05 | 0.9965  |
|  |   |   |   |   |
|  CD4 | 6 hour | 0.97 | 0.94 to 1.00 | 0.9981  |
|   | 7 day | 1.02 | 0.99 to 1.06 | 0.9980  |
|   | 11 day | 1.03 | 0.99 to 1.07 | 0.9976  |
|   | 14 day | 0.99 | 0.96 to 1.03 | 0.9973  |
|  |   |   |   |   |
|  CD8 | 6 hour | 0.98 | 0.94 to 1.02 | 0.9973  |
|   | 7 day | 0.99 | 0.94 to 1.05 | 0.9951  |
|   | 11 day | 1.01 | 0.97 to 1.05 | 0.9968  |
|   | 14 day | 1.00 | 0.95 to 1.06 | 0.9947  |
|  |   |   |   |   |
|  CD16/56 | 6 hour | 0.98 | 0.93 to 1.03 | 0.9950  |
|   | 7 day | 0.98 | 0.93 to 1.04 | 0.9945  |
|   | 11 day | 0.96 | 0.92 to 1.01 | 0.9960  |
|   | 14 day | 0.95 | 0.90 to 0.99 | 0.9962  |
|  |   |   |   |   |
|  CD19 | 6 hour | 1.00 | 0.97 to 1.03 | 0.9985  |
|   | 7 day | 1.01 | 0.95 to 1.07 | 0.9944  |
|   | 11 day | 1.01 | 0.96 to 1.06 | 0.9952  |
|   | 14 day | 0.98 | 0.92 to 1.03 | 0.9949  |
|  |   |   |   |   |
|  CD45 | 6 hour | 0.98 | 0.96 to 1.01 | 0.9987  |
|   | 7 day | 1.01 | 0.96 to 1.05 | 0.9964  |
|   | 11 day | 1.03 | 0.99 to 1.06 | 0.9981  |
|   | 14 day | 1.01 | 0.97 to 1.04 | 0.9987  |

In both HIV positive and healthy donors, markers CD3, CD4 and CD8 are recovered well within the acceptance criteria for absolute cell counts.

b. Matrix comparison:

Not applicable.

{6}

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:
Not applicable.

5. Expected values/Reference range:
Not applicable.

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 a substantial equivalence decision.

7

---

**Source:** [https://fda.innolitics.com/submissions/HE/subpart-b%E2%80%94clinical-chemistry-test-systems/GIM/K080552](https://fda.innolitics.com/submissions/HE/subpart-b%E2%80%94clinical-chemistry-test-systems/GIM/K080552)

**Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. If you're preparing [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/), [get in touch](https://innolitics.com/contact).

**Cite:** Innolitics at https://innolitics.com