The use of HaloTag-based technology in flow and laser scanning cytometry analysis of live and fixed cells
1 Immune Disease Institute and Program in Cellular and Molecular Medicine, Children's Hospital Boston and Harvard Medical School, Boston, MA, USA
2 Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
3 National Hematological Scientific Center, Moscow, Russia
4 Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
5 Department of Pediatrics, Harvard Medical School, Boston, MA, USA
BMC Research Notes 2011, 4:340 doi:10.1186/1756-0500-4-340Published: 9 September 2011
Combining the technologies of protein tag labeling and optical microscopy allows sensitive analysis of protein function in cells.
Here, we describe development of applications using protein tag technology (HaloTag (HT)-based) for flow and laser scanning cytometry (LSC). Cell lines, expressing recombinant surface β1-integrin-HT and HT-p65 fusion protein, and a CD4 T cell line (Jurkat) infected with human immunodeficiency virus type 1 (HIV-1) reporter virus expressing the unfused HT (HIV-1Lai-Halo), were stained with different HT ligands and successfully detected by flow cytometers equipped with 488 and 561 nm lasers as well as a laser scanning cytometer (equipped with 488 and 405 nm lasers) alone or combined with cell cycle and viability markers.
Use of HT technology for cytometric applications has advantages over its use in microscopy as it allows for the statistical measurement of protein expression levels in individual cells within a heterogeneous cell population in combination with cell cycle analysis. Another advantage is the ability of the HaloTag to withstand long fixation and high concentration of fixative, which can be useful in research of infectious agents like HIV and/or mycobacteria.