510(k) Report

510(k) · Cleared

Cleared

Coulter STKS Analyzer with CD4 & CD8 Lymphocyte Analysis

K961278510(k) TraditionalCleared Jul 22, 1996110-day reviewClass II21 CFR 864.5220

Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly, last Nov 3, 2026

Coulter Corp. · GKZ Counter, Differential Cell

Cleared on Jul 22, 1996 as substantially equivalent to K922745 (Coulter Immunology, 1993) and 3 other predicates after a 110-day review. Its family tree reaches back 1 generation to 1988.

Decided
Jul 22, 1996
Review
110 days
Class
Class II
Product code
GKZ
Recalls
None
Predicates
4

Its longest line of descent runs back 1 generation to K885093 (1988). 4 ancestors in all. No later device cites it as a predicate yet.

Other ancestors, by year cleared 1993: 3 other ancestorsK885093 · Coulter STKS · Coulter Electronics, Inc. · 19881986198819901992199419961998
Other ancestors, by generation 1 generation back: 3 other ancestors K885093 · Coulter STKS · Coulter Electronics, Inc. · 19880
  1. Root · 1 generation backK885093 Coulter STKSCoulter Electronics, Inc. · 1988
  2. This deviceK961278 Coulter STKS Analyzer with CD4 & CD8 Lymphocyte AnalysisCoulter Corp. · 1996
View FIG. 1 as a table

Line of descent and top descendants

GenerationNumberDeviceApplicantDecidedRecalls
−1K885093Coulter STKSCoulter Electronics, Inc.1988—
0 (this device)K961278Coulter STKS Analyzer with CD4 & CD8 Lymphocyte AnalysisCoulter Corp.1996—

Other ancestors by year cleared

Year clearedDevicesWith a Class I recall
199330
FIG. 1 — Lineage of K961278, 1988–1996Source: FDA 510(k) summaries, read by 510(k) Report · How lineage is built

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Notable FDA decisions, review times and new Class I recalls. See an issue.

Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.

Planning a device in GKZ? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.

Top candidate predicates for a new GKZ device

  1. #1 K250943 Sysmex XR-Series (XR-10) Automated Hematology…score 13.2 · 3 generations · no Class I recall
  2. #2 Held for the reportin the report
  3. #3 Held for the reportin the report
Get a 510(k) Report

What was it cleared against? (4)

Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.

TypeNumberDeviceApplicantDecidedRecalls
*K922745Cyto-Stat/Coulter Clone CD3(IGG1)-Fitc/T4-RD1
Summary page 1
…ercentage and absolute count are only available if using the COULTER® STKS Analyzer with Reticulocyte Analysis. Substantial Equivalence: 510(k) Premarket Notification: K922745 CyTO-STAT®/COULTER CLONE® CD3(IgG1)-FITC/T4-RD1 Monoclonal Antibody Reagent (CD3/CD4) 510(k) Premarket Notification: K922744 CyT…
Coulter Immunology1993—
*K922744Cyto-Stat/Coulter Clone CD 3(IGG1)-Fitc/T8-RD1
Summary page 1
…Equivalence: 510(k) Premarket Notification: K922745 CyTO-STAT®/COULTER CLONE® CD3(IgG1)-FITC/T4-RD1 Monoclonal Antibody Reagent (CD3/CD4) 510(k) Premarket Notification: K922744 CyTO-STAT®/COULTER CLONE® CD3(IgG1)-FITC/T8-RD1 Monoclonal Antibody Reagent (CD3/CD8) 510(k) Premarket Notification: K885093 COU…
Coulter Immunology1993—
*K885093Coulter STKS
Summary page 1
…t (CD3/CD4) 510(k) Premarket Notification: K922744 CyTO-STAT®/COULTER CLONE® CD3(IgG1)-FITC/T8-RD1 Monoclonal Antibody Reagent (CD3/CD8) 510(k) Premarket Notification: K885093 COULTER® STKS Analyzer 510(k) Premarket Notification: K932030 COULTER® STKS Analyzer with Reticulocyte Analysis 4232216-E R 11-…
Coulter Electronics, Inc.1988—
*K932030Coulter STKS with Reticulocyte Analysis Capability
Summary page 1
…COULTER CLONE® CD3(IgG1)-FITC/T8-RD1 Monoclonal Antibody Reagent (CD3/CD8) 510(k) Premarket Notification: K885093 COULTER® STKS Analyzer 510(k) Premarket Notification: K932030 COULTER® STKS Analyzer with Reticulocyte Analysis 4232216-E R 11-94 Product Differences: Product Testing: The…
Coulter Corp.1993—

Also cleared against K922745: 2 other devices →

What descends from it?

No later submission names this one as a predicate yet.

Has anything in its family been recalled? (0 Class I)

No FDA recall names this device.

No ancestor or descendant has a Class I recall.

What does this lineage say?

  • None of the 4 ancestors has a recall.
  • 2 other devices also cite its predicate K922745.

How does its category compare?

All GKZ devices

GKZ Counter, Differential Cell: FDA decisions, review times, recalls and adverse event reports over 20 years.

FDA decisions per year · GKZ

4in 2025

2007: 62008: 62009: 62010: 42011: 32012: 32013: 12014: 32015: 32016: 32017: 42018: 32019: 52020: 12022: 32023: 42024: 32025: 42026 (partial year): 4
2007high 6 (2007) · low 0 (2021)2026

2026 to Oct 25, outlined.

Median 510(k) review, days · GKZ

108in 2025

2007: 117 days median2008: 99 days median2009: 147 days median2010: 290 days median2011: 315 days median2012: 408 days median2014: 165 days median2015: 273 days median2016: 198 days median2017: 280 days median2018: 270 days median2019: 210 days median2022: 638 days median2023: 329 days median2024: 157 days median2025: 108 days median2026 (partial year): 254 days median
2007high 638 (2022) · low 99 (2008)2026

Receipt to decision; years with fewer than 3 clearances left blank.

Recalls per year · GKZ

1in 2025

2007: 372008: 52009: 132010: 272011: 282012: 72013: 62015: 32016: 32017: 32018: 2, 2 Class I2019: 22020: 12022: 42023: 12025: 1
2007high 37 (2007) · low 0 (2014)2026

Class I (2 since 2007) Class II/III not classified

Adverse event reports per year · GKZ

77in 2025

2007: 2682008: 9252009: 5592010: 8962011: 2,9052012: 2,9592013: 3,0702014: 3,1122015: 1,9722016: 3,3382017: 2292018: 4972019: 9082020: 3422021: 3912022: 1982023: 1552024: 1152025: 77
2007high 3,338 (2016) · low 77 (2025)2025

MAUDE reports naming product code GKZ, not matched to any one device; reports are not rates.

View these four charts as a table
YearDecisionsMedian 510(k) review, daysRecalls (Class I)MAUDE reports
2007611737268
20086995925
2009614713559
2010429027896
20113315282,905
2012340872,959
20131—63,070
2014316503,112
2015327331,972
2016319833,338
201742803229
201832702 (2)497
201952102908
20201—1342
20210—0391
202236384198
202343291155
202431570115
20254108177
202642540—

What is it indicated for?

COULTER STKS Analyzer with CD4 and CD8 Lymphocyte Analysis is a complete system consisting of reagents, sample processing accessories, instrument and software. The system is intended “For In Vitro Diagnostic Use” to identify and enumerate CD4+ and CD8+ T lymphocyte percentages and absolute counts in whole blood using either of two versions of a quantitative, automated hematology analyzer and leukocyte differential counter: COULTER® STKS Analyzer or…

Read the full statement (111 words)

COULTER STKS Analyzer with CD4 and CD8 Lymphocyte Analysis is a complete system consisting of reagents, sample processing accessories, instrument and software. The system is intended “For In Vitro Diagnostic Use” to identify and enumerate CD4+ and CD8+ T lymphocyte percentages and absolute counts in whole blood using either of two versions of a quantitative, automated hematology analyzer and leukocyte differential counter: COULTER® STKS Analyzer or COULTER® STKS Analyzer with Reticulocyte Analysis.

The system is also intended to provide the CD4/CDS8 ratio, a complete blood count (CBC) and a white blood cell (WBC) differential. Reticulocyte percentage and absolute count are only available if using the COULTER® STKS Analyzer with Reticulocyte Analysis.

Indications for use read by OCR from a scanned FDA summary, so letters may be misread. Check the PDF before quoting it.

Also cleared against K922745

2 other devices cite the same predicate.

  • K963263Tetraone System for Epics XL Flow Cytometry Systems and Cyto-Stat Tertrachrome…Coulter Corp. · 19971 Class I recall
  • K962768Cyto-Stat Trichrome CD45-Fitc/CD4-Rdi/CD3-PC5 Monoclonal Anitbody Reagent W/Isotypic ControlCoulter Corp. · 1997

More from Coulter Corp.

51 FDA decisions under this applicant name. See the company

  • K993356Coulter Hematology Analyzers with Irf & MRV AnalysesCoulter Corp. · 2000
  • K991070Coulter Z2 AnalyzerCoulter Corp. · 1999
  • K990327Reticone System for Epics XL Flow Cytometry SystemsCoulter Corp. · 1999
  • K990172Tetraone System for Epics XL Flow Cytometry Systems with Cyto-Stat Tetrachrome…Coulter Corp. · 19991 Class I recall
  • K990352Coulter AC T Diff 2 AnalyzerCoulter Corp. · 19991 recall

Recent decisions in GKZ

The GKZ category page

  • K260781Yumizen H550Horiba Abx Sas · 2026
  • K253212XR-Series (XR-10, XR-20) Automated Hematology AnalyzersSysmex America, Inc. · 2026
  • K243348Athelas HomeAthelas, Inc. · 2026
  • K251249Tru Hematology TestTruvian Sciences, Inc. · 2026
  • K250943Sysmex XR-Series (XR-10) Automated Hematology AnalyzerSysmex America, Inc. · 2025

https://510kreport.com/device/K961278 · printed Nov 4, 2026

Cite this page

510(k) Report. “K961278: Coulter STKS Analyzer with CD4 & CD8 Lymphocyte Analysis.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 4, 2026. https://510kreport.com/device/K961278

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Record history
  • FDA decision record loaded May 2, 2026
  • Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
  • Lineage and recalls computed Nov 3, 2026
  • Page last updated Nov 3, 2026