Evaluation of two new fluorochromes, TOTO and YOYO, for DNA content analysis in cells and chromosomes by flow cytometry

Conference · Fri Jan 01 04:00:00 EST 1993 · Cytometry (Baltimore); (United States)

OSTI ID:6574871

Hirons, G T; Crissman, H A ^[1]

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1. Los Alamos National Lab., NM (United States)

The fluorochromes TOTO and YOYO were evaluated for their effectiveness in staining for DNA content analysis by flow cytometry (FCM). The dyes are dimers of thiazole orange (TO) and yellow oxazole (YO), respectively (Molecular Probes, Eugene, OR), and both have a very high quantum efficiency. Spectrofluorometric analysis showed that TOTO and YOYO had little fluorescence until bound to DNA or RNA. YOYO, the brighter of the two dyes, had an emission peak at [approximately]510 nm and TOTO at [approximately]530 nm. Analysis by flow cytometry indicated that cells stained with either dye at a concentration of [approximately]4.0 [mu]M could be preferentially excited at either 457 or 488 nm. Unfixed nuclei and fixed cells both treated with RNase, stained with either TOTO or YOYO, and analyzed by FCM yielded coefficients of variation (CV) comparable to CVs obtained for the same samples stained with mithramycin (MI) when excited at 457 nm and propidium iodide (PI) when excited at 488 nm. Both TOTO and YOYO are also being evaluated for their effectiveness in staining Chinese hamster embryo chromosomes; these results are being compared with results obtained with PI stained chromosomes.

• OSTI ID: 6574871
• Report Number(s): CONF-9303114--
• Conference Information: Journal Name: Cytometry (Baltimore); (United States) Journal Volume: 6
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550300 -- Cytology
59 BASIC BIOLOGICAL SCIENCES
AZOLES
COMPARATIVE EVALUATIONS
CYTOLOGICAL TECHNIQUES
DNA
DYES
EMISSION SPECTROSCOPY
EVALUATION
FLUORESCENCE
FLUORESCENCE SPECTROSCOPY
HETEROCYCLIC COMPOUNDS
LUMINESCENCE
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXAZOLES
SORTING
SPECTROSCOPY
THIAZOLES