Detecting Low-Abundance Targets: Tyramide & Styramide™ Signal Amplification

news November 25 2021

Signal amplification, such as the popular tyramide signal amplification (TSA) technique, are used for detecting low-abundance targets in cells and tissues.

Similar to TSA, Power Styramide™ Signal Amplification (PSA™) imaging uses horseradish peroxidase (HRP), to catalyze the covalent deposition and binding of labeled-Styramide™ substrates onto a target protein or nucleic acid sequence in situ.

PSA™ combines the superior brightness and photostability of iFluor™ dyes with poly-HRP mediated styramide amplification, resulting in stronger signal intensity and better spatial resolution than TSA. PSA™ imaging has 100x greater sensitivity than conventional techniques, plus:

  • Significantly higher precision
  • Intensely bright signal
  • Short and simple protocols

PSA™ is simpler to perform than TSA, has enhanced sensitivity and specificity, and retains compatibility with other techniques.


Comparison: Fluorescence IHC using PSA™ and TSA amplification methods. Human lung adenocarcinoma positive tissue sections were stained with mouse anti-EpCam antibody and then followed by PSA™ method (Top) using iFluor 594™ PSA™ Imaging Kit with Goat Anti-Mouse IgG or TSA method (Bottom) using Alexa Fluor® 594 tyramide. Images were both taken using the TRITC filter set and under the same exposure time. Nuclei were counterstained with Nuclear Blue™ DCS1.


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Sequential immunostaining with iFluor™ PSA™ Imaging kit: EpCam were labeled with rabbit anti-EpCam antibodies and iFluor™ 488 PSA™ Imaging Kit with goat anti-rabbit IgG. Pan-Keratin was labeled with mouse anti-pan Keratin antibodies and iFluor™ 555 PSA™ Imaging Kit with goat anti-mouse IgG. Nuclei were labeled with DAPI.