Building 580, Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT rachael.walker@babraham.ac.uk 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
Rachael is very involved with the flow cytometry community on a local, national and international level.
Awarded International Society for Advancement of Cytometry (ISAC) Scholarship 2012-2014
TrAEL-seq is a robust method for profiling DNA replication genome-wide that works in unsynchronized cells and does not require drugs or nucleotide analogues. Here, we provide an updated method for TrAEL-seq that improves sample quality and includes multiplexing of up to six samples which dramatically improves throughput, and we validate TrAEL-seq in multiple mammalian cell lines. The updated protocol is straightforward and robust yet provides excellent resolution comparable to OK-seq in mammalian cell samples. High resolution replication profiles can be obtained across large panels of samples and in dynamic systems, for example during the progressive onset of oncogene induced senescence. In addition to mapping zones where replication initiates and terminates, TrAEL-seq is sensitive to replication fork speed, revealing effects of both transcription and proximity to replication Initiation Zones on fork progression. Although forks move more slowly through transcribed regions, this does not have a significant impact on the broader dynamics of replication fork progression, and instead replication forks accelerate across the first ∼1 Mb of travel irrespective of local transcriptional activity. We propose that this is a consequence of fewer replication forks being active later in S-phase when these distal regions replicate and there being less competition for replication factors.
P-Rex1 is a guanine-nucleotide factor for the small GTPase Rac (Rac-GEF) that is known to mediate neutrophil migration and ROS production in response to the activation of GPCRs. These roles of P-Rex1 are assumed to require its activation of Rac.
Although spectral flow cytometry has become a ubiquitous tool for cell analysis, the use of spectral cytometry on cell sorters requires additional considerations arising from the unique requirements of sorting workflows. Here, we show that care should be taken when ascertaining the purity of a sort on a spectral cell sorter, as the mismatch of buffers used for initial sample suspension and the buffers used for sort collection can affect the unmixing of the data, potentially giving rise to erroneous purity check results.