In Vivo Fluorescent Labeling of Tumor Cells with the HaloTag® Technology
Jen-Chieh Tseng*, 1, Hélène A Benink3, Mark G McDougall4, Isabel Chico-Calero2, Andrew L Kung1
1 Lurie Family Imaging Center, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
2 Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
3 Research and Development Department, Promega Corporation, Madison,WI, USA
4 Research and Development Department, Promega Biosciences, LLC, San Luis Obispo, CA, USA
Many fluorescent sensors are currently available for in vitro bio-physiological microscopic imaging. The ability to label cells in living animals with these fluorescent sensors would help translate some of these assays into in vivo applications. To achieve this goal, the first step is to establish a method for selectively labeling target cells with exogenous fluorophores. Here we tested whether the HaloTag® protein tagging system provides specific labeling of xenograft tumors in living animals. After systemic delivery of fluorophore-conjugated ligands, we performed whole animal planar fluorescent imaging to determine uptake in tag-expressing HCT116 xenografts. Our results demonstrate that HaloTag ligands containing red or near-infrared fluorophores have enhanced tumor uptake and are suitable for non-invasive in vivo imaging. Our proof-of-concept results establish feasibility for using HaloTag technology for bio-physiological imaging in living animals.
Keywords: Fluorescent imaging, HaloTag, tumor xenograft, in vivo labeling..
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* Address correspondence to this author at the Lurie Family Imaging Center, Dana-Farber Cancer Institute 450 Brookline Avenue, DD 109, Boston, MA 02215, USA; Tel: 617-582-8970; Fax: 617-582-8973; E-mail: firstname.lastname@example.org