Probing single molecules in single living cells

Citation
Ta. Byassee et al., Probing single molecules in single living cells, ANALYT CHEM, 72(22), 2000, pp. 5606-5611
Citations number
49
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences
Journal title
ANALYTICAL CHEMISTRY
ISSN journal
0003-2700 → ACNP
Volume
72
Issue
22
Year of publication
2000
Pages
5606 - 5611
Database
ISI
SICI code
0003-2700(20001115)72:22<5606:PSMISL>2.0.ZU;2-I
Abstract
Single-molecule detection in single living cells has been achieved by using confocal fluorescence microscopy and externally tagged probe molecules. Th e intracellular background fluorescence is substantially higher than that i n aqueous buffer, but this background is continuous and stable and: does no t significantly interfere with the measurement of single-molecule photon bu rsts. As a result, single-molecule data have been obtained on three types o f fluorescent probes at spatially resolved locations (e.g., cytoplasm and n ucleus) inside human HeLa cells. First, the iron transport protein transfer rin labeled with tetramethylrhodamine undergoes rapid receptor-mediated end ocytosist and single transferrin molecules are detected inside living cells . Second, the cationic dye rhodamine 6G (R6G) enters cultured cells by a po tential-driven process, and single R6G molecules are observed as intense ph oton bursts when they move in and out of the intracellular laser beam. Thir d, we report results on synthetic oligonucleotides that are tagged with a f luorescent dye and are taken up by living cells via a passive, nonendocytic pathway.