Rachael Walker

Rachael Walker
Rachael Walker
Rachael Walker
Head of Flow Cytometry Facility
Rachael Walker

Head of Flow Cytometry: Dr Rachael Walker

Building 580, Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT
01223 496559

Rachael has over 15 years of experience in flow cytometry and cell sorting and over a dozen years of working in flow cytometry core facilities. Rachael joined the core in September 2012, following 7 years running Flow Cytometry Core Facilities at the University of Cambridge.

Rachael has extensive experience in analysis and sorting cells of differing types including; immunology, cell biology, stem cell biology, large cells such as cardiomyocytes, c. elegans eggs; organelles such as nuclei. Rachael can provide expertise in experimental setup, optimisation and analysis. She can help with optimal instrument set up, post-acquisition analysis of data and preparing figures for papers.


2005- PhD in Tissue Engineering, Department of Clinical Engineering, University of Liverpool
2001- BMedSc (Honours), Biomedical Materials Science, University of Birmingham

Flow Cytometry community

Rachael is very involved with the flow cytometry community on a local, national and international level.

Rachael’s work includes:

Awarded International Society for Advancement of Cytometry (ISAC) Scholarship 2012-2014

  • Awarded ISAC ‘Emerging Leader in Shared Resource Laboratory’ Scholarship 2014-2016
  • Mmeber of ISAC Flow Cytometry Content Task Force and SRL Emerging Leaders Committee
  • Member of ISAC Program committee for CYTO conferences since 2010
  • Chair of local Mid-Anglia Cytometry (MACC) meetings
  • Secretary of flowcytometryUK, also one of main organisers of flowcytometryUK national annual meetings
  • Fellow and member of Royal Microscopical Society (RMS) Cytometry Section
  • ​Regular contributor to ‘Flow Cytometry’ Channel on Bitesize Bio website.
  • Regular reviewer of papers for several journals and reviewer of international and national grants.

Latest Publications

Cheetham M, Davies D, Hall C, Petersen CC, Schulte R, Walker R Flow Cytometry

Cell sorting is a technique commonly used in academic and biotechnology laboratories in order to separate out cells or particles of interest from heterogeneous populations. Cell sorters use the same principles as flow cytometry analyzers, but instead of cell populations passing to the waste of the instrument, they can be collected for further studies including DNA sequencing as well as other genomic, in vitro and in vivo experiments. This chapter aims to give an overview of cell sorting, the different types of cell sorters, details on how a cell sorter works, as well as protocols that are useful when embarking on a journey with cell sorting.

+view abstract Methods in molecular biology (Clifton, N.J.), PMID: 38526785

Hornigold K, Baker MJ, Machin PA, Chetwynd SA, Johnsson AK, Pantarelli C, Islam P, Stammers M, Crossland L, Oxley D, Okkenhaug H, Walker S, Walker R, Segonds-Pichon A, Fukui Y, Malliri A, Welch HCE Signalling , Imaging , Mass Spectrometry , Bioinformatics , Flow Cytometry

Rac GTPases are required for neutrophil adhesion and migration, and for the neutrophil effector responses that kill pathogens. These Rac-dependent functions are impaired when neutrophils lack the activators of Rac, Rac-GEFs from the Prex, Vav, and Dock families. In this study, we demonstrate that Tiam1 is also expressed in neutrophils, governing focal complexes, actin cytoskeletal dynamics, polarisation, and migration, in a manner depending on the integrin ligand to which the cells adhere. Tiam1 is dispensable for the generation of reactive oxygen species but mediates degranulation and NETs release in adherent neutrophils, as well as the killing of bacteria. , Tiam1 is required for neutrophil recruitment during aseptic peritonitis and for the clearance of during pulmonary infection. However, Tiam1 functions differently to other Rac-GEFs. Instead of promoting neutrophil adhesion to ICAM1 and stimulating β2 integrin activity as could be expected, Tiam1 restricts these processes. In accordance with these paradoxical inhibitory roles, Tiam1 limits the fMLP-stimulated activation of Rac1 and Rac2 in adherent neutrophils, rather than activating Rac as expected. Tiam1 promotes the expression of several regulators of small GTPases and cytoskeletal dynamics, including αPix, Psd4, Rasa3, and Tiam2. It also controls the association of Rasa3, and potentially αPix, Git2, Psd4, and 14-3-3ζ/δ, with Rac. We propose these latter roles of Tiam1 underlie its effects on Rac and β2 integrin activity and on cell responses. Hence, Tiam1 is a novel regulator of Rac-dependent neutrophil responses that functions differently to other known neutrophil Rac-GEFs.

+view abstract Frontiers in immunology, PMID: 38077328

Belkina AC, Roe CE, Tang VA, Back JB, Bispo C, Conway A, Chakraborty U, Daniels KT, de la Cruz G, Ferrer-Font L, Filby A, Gravano DM, Gregory MD, Hall C, Kukat C, Mozes A, Ordoñez-Rueda D, Orlowski-Oliver E, Pesce I, Porat Z, Poulton NJ, Reifel KM, Rieger AM, Sheridan RTC, Van Isterdael G, Walker RV Flow Cytometry

The purpose of this document is to provide guidance for establishing and maintaining growth and development of flow cytometry shared resource laboratories. While the best practices offered in this manuscript are not intended to be universal or exhaustive, they do outline key goals that should be prioritized to achieve operational excellence and meet the needs of the scientific community. Additionally, this document provides information on available technologies and software relevant to shared resource laboratories. This manuscript builds on the work of Barsky et al. 2016 published in Cytometry Part A and incorporates recent advancements in cytometric technology. A flow cytometer is a specialized piece of technology that require special care and consideration in its housing and operations. As with any scientific equipment, a thorough evaluation of the location, space requirements, auxiliary resources, and support is crucial for successful operation. This comprehensive resource has been written by past and present members of the International Society for Advancement of Cytometry (ISAC) Shared Resource Laboratory (SRL) Emerging Leaders Program https://isac-net.org/general/custom.asp?page=SRL-Emerging-Leaders with extensive expertise in managing flow cytometry SRLs from around the world in different settings including academia and industry. It is intended to assist in establishing a new flow cytometry SRL, re-purposing an existing space into such a facility, or adding a flow cytometer to an individual lab in academia or industry. This resource reviews the available cytometry technologies, the operational requirements, and best practices in SRL staffing and management.

+view abstract Cytometry. Part A : the journal of the International Society for Analytical Cytology, PMID: 37941128

Group Members

Rachael Walker

Head of Flow Cytometry Facility

Larissa Catharina Costa

Flow Cytometry Technician

Yulia Chupalova

Flow Cytometry Specialist

Kleopatra Dagla

Flow Cytometry Assistant

Rita Dapaah

Flow Cytometry Technician

Christopher Hall

Deputy Flow Cytometry Manager

Sam Thompson

Flow Cytometry Specialist