Considerable effort has addressed the challenge of specifically labeling many different protein types. In this regard, Array Tomography constitutes the most important technical advance by allowing multiple proteins to be co-localized in a single sample.
In Array Tomography, thin serial LR-white resin-embedded sections (~30-250 nm) laid on glass slides are immuno-stained and imaged by fluorescence. The antibodies can be washed away and the entire process can be repeated with another protein of interest.
A clear advantage of section immuno-staining compared to whole sample staining is the efficiency of labeling. Sectioning overcomes the problems of antibody penetration. Further, three dimensional reconstruction can be made with excellent z-resolution, and volumetric imaging of a large number of antigens in a specimen is obtained.
We are experienced with Array Tomography and at combining it with sub-diffraction resolution imaging.
Micheva and Smith, “Array Tomography: A New Tool for Imaging the Molecular Architecture and Ultrastructure of Neural Circuits”, Neuron 55, 25–36,2007