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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 News06—09/09/09 — Seta BioMedicals, LLC presented several posters on novel fluorescent labels at MAF-11 in Budapest. 08/05/09 — Seta BioMedicals, LLC announces the release of SeTau-655 and SeTau-665 — the first of a new class of next generation dyes combining exceptional brightness, chemical stability (towards H2O2/ozone) and extremely high photostability. Please contact us for more information on these exciting new dyes. 10/10/08 — 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.
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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. SETA, Square and SeTau dyes are series of dyes that span the whole visible spectrum and the NIR. They are available with various functionalities: carboxylic acids, as amine-reactive dyes (NHS ester) for labeling of amino groups on peptides, proteins or amino-modified DNA, as maleimides for coupling to thiol-groups in proteins and thiol-modified oligos and as amine-modified labels (on request). All these reagents are available in either a 1 mg or 5 mg unit size. Advantages
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:These Products are for research purposes only and may not be used for commercial, clinical, diagnostic or any other use. The Products are subject to proprietary rights of SETA BioMedicals, LLC. There is no implied license for commercial use with respect to the Products and a license must be obtained directly from SETA BioMedicals with respect to any proposed commercial use of the Products. “Commercial use” includes but is not limited to the sale, lease, license or other transfer of the Products or any material derived or produced from them, the sale, lease, license or other grant of rights to use the Products or any material derived or produced from them, or the use of the Products to perform services for a fee for third parties (including contract research).
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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 lampSeta-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) with lifetimes in the order of 10 to 32 ns for lifetime assays and for measurement of high molecular weight analytes with molecular weights as high as 65 kDa in homogeneous fluorescence polarization assays. These labels are PURETIME alternatives and feature large Stokes’ shifts including high extinction coefficients and quantum yields (brightness). Try them out and see for yourself!
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).Square dyes such as Square-655 are the most sensitive probes currently on the market for the detection of proteins. These dyes have extremely low quantum yields in aqueous solution and quantum yields of up to 80% when non-covalently bound to proteins. Up to a several hundred-fold increase of the fluorescence intensity has been observed with some Square Probes upon binding to proteins, which makes them perfectly suited for gel and capillary electrophoresis applications.
Protein concentration dependent increase in fluorescence intensity of Square-655 (K8-1500) |
Seta and Square dyes, probes and labels are useful for applications in the following areas:
Relative pH-dependent emission spectra of Square-650-pH-IgG conjugates. For more information we refer you to the following publication: Anal. Biochem., 390, 136–140 (2009)SETA BioMedicals, LLC also offers dyes for the assessment of cell necrosis (disruption of cell membranes) and phagocytic events: 11th Conference on Methods and Applications of Fluorescence (MAF-11), Budapest (Hungary), 6–9 September 2009, P. 118
Recently SETA BioMedicals, LLC developed a generic fluorescence lifetime (FLT) based reagent suitable for the measurement of small molecular weight antigens based on a FLT-based immuno-assay: Bioconjugate Chem., 20, 1807–1812 (2009)
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.
If you require help with selecting your labels for a specific application click here. |