Customer Spotlight

Taking a New Look at Toxoplasma gondii with Cytation™ 3

Washington University in St. Louis School of Medicine


Dr. David Sibley’s lab at the Washington University in St. Louis School of Medicine, Department of Molecular Microbiology studies the pathogenic, intracellular parasite, Toxoplasma gondii. This parasite causes toxoplasmosis in warm-blooded animals, and is a model for understanding other intracellular parasites and the diseases they cause. Ms. Beth Selleck is a graduate student in Dr. Sibley’s lab, researching the interaction between the host innate immune system and the T. gondii parasite, and specifically looking at how infected cells are able to kill or prevent the parasite’s replication.

Beth works with tissue culture and immunofluorescence assays to quantify total T. gondii-infected host cells, percentages of parasites with host proteins recruited to the parasite’s detriment, and the extent to which T. gondii are able to replicate within the host cell under different conditions.

The lab also incorporates a variety of different techniques and assays to ascertain how T. gondii mutants survive, replicate or invade host cells. In the process of researching automated imagers with cell counting abilities for the lab as an alternative for moving to a high-throughput core facility, Dr. Sibley was introduced to BioTek’s Cytation™ 3 Cell Imaging Multi-Mode Reader. After considering and demonstrating several products, the Cytation 3 was selected for its superior imaging and high-throughput capabilities. Additionally, since a BioTek reader is currently used for BCA and colorimetric assays, lab personnel were familiar with Cytation 3’s integrated Gen5™ Software.

Installation and training for members of the Sibley lab and a neighboring lab took one day. Beth recalls, “The training was totally sufficient to get us started, and once we were set up and running more experiments, we asked questions of our local BioTek rep about specific applications, and he was able to provide us helpful answers and tips.” Beth found BioTek’s service to be “really exceptional”, especially the local sales representative and field technicians, citing their technical and application-specific expertise, and fast response times.

Cytation 3’s combination of multi-mode microplate reading and imaging, combined with powerful imaging and data analysis, allows Beth and other users to dramatically increase the complexity of their experiments, including increased time points, parasite strains and conditions without increasing the time needed to obtain the data. Multi-mode reading provides flexibility for the lab to run both fluorescence (see image) and luminescence assays on T. gondii, and the imaging module has almost completely replaced manual cell counting since installation. Beth greatly appreciates the reduced time spent manually counting cells and also notes, “It’s also allowed me to analyze experiments in ways we hadn’t done previously using traditional microscopy, including measuring the size and area of replicated parasite vacuoles.” Housing the Cytation 3 in their lab instead of using a core facility reduces the time spent on testing experimental conditions and screening staining protocols, and the automated features decrease potential bias so that results may be compared between different individuals and laboratories.

10x image of HFF cells, showing dead cell nuclei stained with ethidium bromide dimer (red), T. gondii (green) and DAPI (blue).
10x image of HFF cells, showing dead cell nuclei stained with ethidium bromide dimer (red), T. gondii (green) and DAPI (blue).


Washington Uniersity in St Luis

To learn more about Washington University in St. Louis School of Medicine, visit their web site.
Thanks to Dr. David Sibley at Washington University for sharing his BioTek experience.

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