Labeling Rectal Tissue with Fluorescent Probes Conjugated to Phallotoxins and Lectins
In order to localize a red fluorescent tag to F-actin in the sample of rat rectum tissue presented in the digital image above, the specimen was labeled with Alexa Fluor 568 conjugated to phalloidin, a phallotoxin derived from the toxic death cap mushroom. Oregon Green 488 conjugated to the lectin wheat germ agglutinin, which selectively binds to N-acetylglucosamine and N-acetylneuraminic residues, was also applied to the tissue sample, as was the DNA probe Hoechst 33342. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.