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Probes and Labels for Biomedical Research |
 AnnouncementsUrbana, IL, November 1, 2006 — SETA BioMedicals, LLC has entered into an exclusive license agreement with PerkinElmer Life and Analytical Sciences to provide dyes for their HTS assays. |
Recent News10/10/08 — Seta-646-mono-NHS, a new, extremely bright and photostable, mono-reactive protein label and superior Cy5 or Alexa 647 replacement was added. 03/30/08 — Seta-660-di-NHS, an extremely bright and photostable, bis-reactive NHS-ester and superior Cy5.5 or Alexa 660 replacement was added to our product portfolio. 03/10/08 — SETA-FRET version 2.02 — Software for calculation of the Förster energy transfer distance is available. 02/12/08 — Seta-633-di-NHS, a bright, bis-reactive protein label is well-suited for labeling of proteins and antibodies. 11/30/07 — Seta-632-mono-NHS a new, extremely bright and photostable, mono-reactive protein label excitable with a 635-nm diode laser was added. 10/01/07 — Seta-633-mono-NHS is a hydrophilic, mono-reactive label for proteins and other biomolecules. This fluorescent label has an extinction coefficient of 250,000 M–1cm–1 and quantum yields of up to 70% when labeled to proteins. 07/07/07 — Seta-635-mono-NHS a new, extremely bright and photostable, mono-reactive protein label is well-suited for single molecule measurements and microarrays. |
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SETA BioMedicals, LLC provides fluorescent tools for biomedical, pharmaceutical, and environmental research. These dyes, probes and labels cover the entire visible spectrum and the near infrared (NIR). SETA BioMedicals, LLC also offers extremely bright fluorescent classification dyes for encoding of microspheres (beads), used in High-Throughput Screening (HTS) and Multiplexed Analysis Systems. Support for the development of these probes and labels has been obtained from US and European Union funding agencies.
Saccharomyces cerevisiae cells stained with Alexa 647 (NHS ester) and Square-635-di-NHS before and after 5 min of observation with an Olympus IX-71 fluorescent microscope. A 50% gray filter and a Cy5 ex/em filter set were used
Intellectual Property Disclaimer:
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The red-excitable dyes of the Square and Seta series have advantages as compared to e.g. Cy5, Cy5.5, Cy7, and Alexa 647:
The photostability of Seta dyes typically exceeds that of Alexa and Cy dyes.
Relative decrease of the emission of Seta-646-mono-NHS as compared to Cy5 and Alexa 647 upon irradiation with a Xenon lamp
Seta-633-mono-NHS is a hydrophilic, mono-reactive label for proteins and other biomolecules. It is extremely bright and has a low tendency for self-quenching even at higher D/P ratios. The extinction coefficient is 250,000 M–1cm–1 and quantum yields as high as 70% were obtained from conjugates with this long-wavelength marker.
The fluorescence lifetime of Seta-635-NH-di-NHS in aqueous buffer solution is twice as long as that of Cy5 while the quantum yield is comparable therefore making it a perfect label for use in homogeneous fluorescence polarization assays.
The mono-NHS ester Sqaure-660-mono-NHS is a very useful label for gel-electrophoresis applications and gives excellent results with regards to labeling efficiency and sensitivity (Cydye DIGE replacement).
Seta-660-di-NHS, a reactive label is a brighter replacement for Alexa 660, Alexa 647 or Cy5.5 with quantum yields of up to 50% and higher photostability.
Quantum yield vs. dye-to-protein ratio of Seta-660 — IgG conjugates in phosphate buffer (pH 7.4)
Protein conjugates of Seta-646-mono-NHS are much brighter than Cy5 conjugates and show similar excitation and emission maxima and therefore can be measured using the Cy5 filter set.
Unlike the widely used red Cy and Alexa dyes that are excitable only with a red diode laser, some of the red-excitable Square and Seta dyes are also excitable with the blue 405-nm laser diode.
SETA BioMedicals, LLC also offers long lifetime labels (SeTau labels) for lifetime assays and for measurement of high molecular weight analytes with molecular weights as high as 65 kDa in homogeneous fluorescence polarization assays
Changes in Fluorescence Polarization of
SeTau-425-labeled
HSA (MW ~ 65 kDa) upon titration with anti-HSA. The labeled HSA
species has still a relatively low polarization of 165 mP and only
upon addition of antibody the polarization increases gradually to its
final value of 335 mP, which demonstrates the usefulness of this label
for the measurement of high-molecular-weight antigens in a
Fluorescence Polarization Immunoassay (FPA) |
Seta and Square dyes, probes and labels are useful for applications in the following areas:
SIF-coated vs. non-coated glass fluorescence signal ratio at various wavelengths for the model immunoassays using Seta-670-mono-NHS (A) and Seta-635-NH-mono-NHS (B)
Wide field image for anti-rabbit IgG antibodies labeled with Seta-670-mono-NHS deposited on a glass slide (D/P=3.2) obtained using 635 nm excitation (~4 mW) and observed through a 685/35 nm bandpass filter. (A) before and (B) after photobleaching of a single IgG protein/spot (marked by arrow). (C) typical fluorescence intensity trajectory during photobleaching illumination (~12 mW) for a D/P=3.2 conjugate. The selected spot undergoes a three steps irreversible photobleaching. The inserts show the time-resolved photon histograms and calculated fluorescence lifetimes for the corresponding regions of fluorescence intensity trajectory |
Last modified: 11/17/08
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