Combined immunofluorescence and high-voltage electron microscopy of cultured mammalian cells, using an antibody that binds to glutaraldehyde-treated tubulin.

An antibody against tubulin that binds specifically to microtubules in glutaraldehyde-fixed cells has been prepared. Sodium dodecyl sulfate-denatured tubulin treated with glutaraldehyde was used to immunize rabbits. In glutaraldehyde-fixed cells the fluorescent image of this antibody reveals a fine lattice of microtubules around the nucleus of PtK1 (Potorous tridactylis) cells and many uniformly fluorescent microtubules in the peripheral cytoplasm. In cells fixed with formaldehyde the microtubules appear to have a similar distribution, but the fluorescent image is much less uniform. Combined high-voltage electron microscopy and immunofluorescent studies reveal that microtubules are found in the cytoplasm in the same region as the fluorescent antibody stain.