Proposing November 12th as International Flow Cytometry Day: Celebrating History, Inspiring Society

Abstract

True innovation in biology and technology often begins where separate disciplines meet. On November 12, 1965, more than 60 years ago, Mack Fulwyler published a landmark paper in Science that fundamentally changed the course of biomedical research [1]. By adapting inkjet droplet-deflection technology for biological use, he achieved electrostatic cell sorting based on electronic volume measurements [2]. That breakthrough brought together precision fluidics, instrumentation engineering, and single-cell biology, creating a new foundation for modern flow cytometry and cell sorting [3-5]. To honor this legacy and recognize the remarkable growth of the global cytometry community, we propose formally establishing November 12 as International Flow Cytometry Day.

Establishing an annual point of reference would allow the global scientific community to reflect on our shared history while driving future innovation. Central to this initiative could be an international, synchronized symposium tracing the field's evolution—from Mack Fulwyler's early fluidics concepts and the landmark historical developments documented across Cytometry Part A [4, 5] to state-of-the-art advances in high-dimensional multiomics, spectral cytometry, mass cytometry, and label-free imaging. Beyond celebrating technical milestones, this annual event would serve as a vital platform to advocate for standardized data formats, robust quality control, and enhanced reproducibility across clinical and academic settings. With endorsement from scientific societies, academic institutions, and industry partners, International Flow Cytometry Day can mature into an enduring framework for field-wide education and international collaboration.

Equally important, this initiative seeks to recognize the diverse pioneers who transformed an engineering milestone into an indispensable scientific platform. While Fulwyler pioneered droplet deflection making electrostatic cell sorting possible, the discipline truly blossomed through the combined efforts of researchers who developed novel fluorophores, monoclonal antibody applications, advanced computational algorithms, and shared resource facilities that brought flow cytometry into everyday biomedical research.

Women scientists, in particular, have played a foundational role in this journey, from the early days of flow cytometry cell sorting, hybridoma technology, optical biophysics, and pioneering software algorithms for list-mode data acquisition, automated gating, and data standardization (FCS), to contemporary leadership in high-dimensional computational cytomics, clinical translation, and core facility management [6-15]. By explicitly honoring their contributions through the literature, International Flow Cytometry Day will ensure that the history of cytometry is told not only through its defining technical breakthroughs but also through the community that turned those breakthroughs into a living discipline.

Finally, this initiative offers an unprecedented opportunity to bring cytometry cell analysis out of specialized laboratories and into the public eye. Standardized educational toolkits, school outreach programs, and interactive demonstrations can inspire early-career scientists by demonstrating how single-cell analysis shapes immunology, oncology, cell therapy, and environmental health. At the same time, research centers and core facilities can also host open events and digital showcases to make single-cell analysis more accessible, thereby helping visitors understand how cytometry contributes to clinical diagnostics, hematology, basic research, and public health.

Flow cytometry has evolved from an ambitious engineering achievement into a cornerstone of contemporary bioscience. Establishing November 12 as International Flow Cytometry Day will provide our diverse and interdisciplinary community with a shared occasion to celebrate the physics, instrumentation, biological insights, and people that continue to drive the advancement of this field. We welcome feedback, support, and collaboration from ISAC, the readers of Cytometry Part A, and the broader cytometry community in helping turn this proposal into a lasting international observance.

Jordi Petriz: conceptualization, writing – original draft, writing – review and editing, resources, supervision, investigation, funding acquisition, project administration. Marc Sorigue: writing – review and editing, conceptualization. Alberto Álvarez-Barrientos: conceptualization, writing – review and editing. José Enrique O'Connor: conceptualization, writing – review and editing.

The authors declare no conflicts of interest.

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.