Murine Mutagenesis Core

Producing mice models to support neuroscience research

NINDS Institutional Center Core Grant to Support Neuroscience Research: Murine Mutagenesis Core (MMC)


The mission of MMC is to effectively produce genetically engineered mice models (knock-ins, knock-outs, and inducible knock-outs) using both ES cell technologies and CRISPR-based techniques. We strive to stay abreast of cutting-edge developments and to incorporate these in order to best serve our investigators. The MMC promotes interactions among a diverse group of neuroscientists at Johns Hopkins University. This has facilitated the completion of many studies that represent advances relevant to key issues in basic and clinical neuroscience, as illustrated in our List of Publications and List of Mutagenic Mice presenting work supported by the MMC.

The MMC is funded by an NINDS Core Center Grant (P30 NS050274: "JHU Center for Neuroscience Research"). Services by this Core are available to three groups of investigators: (1) the thirteen Primary Center Investigators who are co-PIs of this P30 grant; (2) NINDS-funded investigators at The Johns Hopkins School of Medicine; and (3) on a case by case basis, other non-NINDS-funded neuroscience investigators at JHU. All applications for use of Core facilities are carefully evaluated by Core personnel and directors, and services are allocated based on availability and guidelines that govern this NINDS Core funding mechanism.
Questions regarding eligibility to utilize Core Services can be addressed to the MMC Director (Xinzhong Dong, or the P30 Center Director (Alex Kolodkin,


The MMC is located in Room 915, Wood Basic Science Building, at 725 North Wolfe Street
Phone: 410-614-3858


A great deal of expertise is available to users of the MMC. Director Xinzhong Dong has considerable knowledge in using a variety of relevant techniques, including both ES cell and CRISPR/Cas9 technologies, and thus is able to facilitate productive collaboration between the MMC and individual labs within the neuroscience community.  Chip Hawkins, manager of the Johns Hopkins Transgenic Core Laboratory, is available to share his extensive experience in creating transgenic mice. Finally, the MMC benefits from the input of Dr. Randall Reed, (Molecular Biology and Genetics Department), who has agreed to serve as a consultant for the MMC to provide his invaluable expertise on novel CRIPSR/Cas9 targeting design strategies. His input on project design, particularly for projects involving incorporation of large strands of DNA, will be invaluable for generating desired mice as efficiently as possible.


The MMC supports the generation of transgenic mice for research in a variety of ways. We continue to provide ES cell line generation using state-of-the art targeting strategies. In addition, we provide assistance in the design and implementation of CRIPSR/Cas9 targeting to generate transgenic mice with improved speed and efficiency. We also provide cryopreservation of sperm to assist in archiving valuable mouse lines. Finally, an important role of the MMC is to offer guidance on the design of targeting constructs and to provide training and consultation on other genome engineering technologies including BAC transgenics, integrase-mediated knock-ins, and CRISPR based genomic editing.

The development of innovative technologies is an important goal of the MMC, allowing us to provide services to the neuroscience community which might not otherwise be available. Recent or ongoing projects illustrative of this aim include the use of embryos derived from investigators' existing mutant mouse lines to generate a second mutation in an existing line, the use of large ssDNA to generate conditional alleles, the performance of large knockin insertions, and the utilization of alternative CRISPR/Cas9 proteins for allele generation. The Core's commitment to the development of innovative and cutting-edge techniques provides a unique opportunity for investigators to take on risky projects that might not otherwise be possible.


Prior to the initiation of a project, a brief meeting is generally required between the investigator and MMC facility staff resulting in a mutually acceptable research strategy. This strategy will outline specifics of the project including knockout strategy, KO construct design, screening assays, and other procedural issues relevant to the generation of targeted ES cells.

In addition, a completed Application for Service (Application for Service:ES Cells; Application for Service:KOMP cells; or Application for Service:Crispr), signed by the principal investigator, forwarded to Core Manager (Chip Hawkins;, and approved by the Core Director, will be required. The Core Director will prioritize the service requests according to the relevance of the project to the goals of the NIINDS and the potential for the project to facilitate the development of new and improved technologies and techniques.

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