Visible Fluorescent Secondary Antibodies for Microscopy.

LI-COR offers VRDye™ 490, VRDye 549, and IRDye^® 650 dye-labeled secondary antibodies and protein labeling kits. These new secondaries can be used for for a variety of applications, including immunofluorescence microscopy and flow cytometry. Just like our IRDye dye-labeled secondary antibodies, these new visible fluorescence antibodies are highly cross-adsorbed.

The dyes are conjugated to the same antibodies as the existing IRDye secondary antibodies, which are used for Western blotting and In-Cell Western™ Assay applications. This gives researchers the ability to correlate microscopy and flow data with Western blot and cell-based assay data.

The visible fluorescence secondary antibodies are suitable for multiplex experiments when combined with other secondary antibodies labeled with proper fluorescent dyes and using instrumentation with appropriate excitation and detection capabilities.

If you are doing flow cytometry or microscopy and need dye-labeled secondary antibodies in the visible fluorescence range, we can help. LI-COR now offers IRDye^® and VRDye™ dye-labeled secondary antibodies for 650nm, 549nm, and 490nm channel detection. VRDye secondary antibodies are are highly cross-adsorbed - just like our IRDye secondary antibodies, making them suitable for multi-color detection. Figure 1 below is an example of immunofluorescence staining using VRDye 490 Goat anti-Rabbit secondary antibody. Figure 2 below is an example of immunofluorescence staining using VRDye 549 Goat anti-Rabbit secondary antibody.

In addition, many researchers use labeled primary antibodies for flow cytometry. LI-COR also offers visible fluorescent dye protein labeling kits that are ideal for customers who need to label custom monoclonal antibodies for this application. Visit our website for more information on LI-COR visible fluorescence antibodies and protein labeling kits or to order them for your research.

Are you ready to try IRDye Infrared Dyes and secondary conjugates or VRDye visible fluorescent secondaries on your epifluorescent microscope? Check out the recommended configurations for Olympus and Zeiss microscopes - and go image!

**Figure 1. Immunofluorescence staining of tubulin protein in HeLa cells.** Cells were cultured on cover slips. After fixation and permeabilization, cells were incubated with rabbit anti-tubulin mAb (CST), followed by VRDye 490 Goat anti-Rabbit IgG (P/N 926-49020). Nuclei were stained with DAPI. Image acquired with Olympus IX81 microscope.

**Figure 2. Immunohistochemistry staining of EGFR protein on F98-EGFR tumor slides.** F98-EGFR tumors were snap-frozen in O.C.T.™ compound and sectioned at 4-µm thickness. After fixation and permeabilization, cells were incubated with rabbit anti-EGFR mAb (CST), followed by detection with VRDye™ 549 Goat anti-Rabbit IgG (P/N 926-54020). DAPI was used to stain the nuclei. Image acquired on Olympus IX81 microscope.

Need Visible Fluorescent Secondary Antibodies for Flow Cytometry or Microscopy?