ATTO dyes

Dye Abs (nm) Em (nm) ε (M−1cm−1) QY
ATTO 390 390 479 24,000 90
ATTO 425 436 484 45,000 90
ATTO 465 453 508 75,000 55
ATTO 488 501 523 90,000 80
ATTO 495 495 527 80,000 45
ATTO 520 516 538 110,000 90
ATTO 532 532 553 115,000 90
ATTO 550 554 576 120,000 80
ATTO 565 563 592 120,000 90
ATTO 590 594 624 120,000 80
ATTO 594 601 627 120,000 85
ATTO 610 615 634 150,000 70
ATTO 611X 611 681 100,000 35
ATTO 620 619 643 120,000 50
ATTO 633 629 657 130,000 64
ATTO 635 635 659 120,000 25
ATTO 637 635 659 120,000 25
ATTO 647 645 669 120,000 20
ATTO 647N 644 669 150,000 65
ATTO 655 663 684 125,000 30
ATTO 665 663 684 160,000 60
ATTO 680 680 700 125,000 30
ATTO 700 700 719 120,000 25
ATTO 725 729 752 120,000 10
ATTO 740 740 764 120,000 10
Abs = absorption maximum#, Em = emission maximum#,
ε = molar extinction coefficient, QY = fluorescence Quantum Yield#
# in water

ATTO Dyes are a series of fluorescent labels and dyes manufactured by ATTO-TEC GmbH in Siegen, Germany. The dyes have been designed for application in the area of life science, e.g. labeling of DNA, RNA and proteins as well as analytical applications, in particular fluorescence microscopy.

The ATTO Dye series covers a spectral range from 390 nm in the UV up to 740 nm in the near infrared allowing excitation with most commonly used light sources. The dyes typically are derivatives of coumarins, rhodamines, carbopyronins and oxazines. They are commercially available as free carboxylic acids, amine reactive N-hydroxy-succinimidyl-esters (NHS-ester) or thiol reactive maleimides.

Many common fluorescent labels, e.g. Fluorescein (FITC), show rather low photostability. As a result sensitivity and quality of imaging are limited if high-intensity laser excitation is used and processes are to be observed over long periods of time. This is a serious draw-back in microscopy and other techniques based on the confocal principle, e.g. in single-cell detection applications. In contrast to some widely used older dyes, the patented ATTO-labels are designed to be much more stable under prolonged irradiation.

Compared with other labels especially for the red region of the spectrum, ATTO-labels show excellent photostability and brightness. ATTO 647N fluoresces twice as strong as Cy5 in aqueous solution.[1]

In addition many common fluorescent labels especially cyanine dyes like Cy5 deteriorate even without any irradiation (in the dark), in particular when exposed to small concentrations of ozone present in the laboratory atmosphere.[2] Under identical conditions of ozone exposure the new dyes ATTO 633, ATTO 647N and ATTO 655 last up to 100 times longer than cyanines like Cy5 and Alexa Fluor 647.[3][4] This is very important in microarray applications, where the dye molecules are located at the surface and thus are in direct contact with the atmosphere.

Similar lines of fluorescent dyes provide an alternative to the Atto Dyes (see also the list in Category:Fluorescent dyes).

References

  1. ↑ ATTO-TEC Catalogue 2009/2010 p.17
  2. ↑ Fare TL, Coffey EM, Hongyue D, et al. Effects of Atmospheric Ozone on Microarray Data Quality. Analytical Chemistry. 2003;75:4672-4675.
  3. ↑ ATTO-TEC Catalogue 2009/2010 p.16
  4. ↑ BioFiles Volume 2, Number 5, 2007