An immunocytochemical method for the visualization of tubulin-containing structures in the egg of Xenopus laevis.

Tubulin can be isolated and purified from Xenopus laevis eggs through modification of Olmstedt's (1970) tubulin isolation method, viz. by repeating the vinblastin precipitation step after resuspension of the sediment in a detergent-containing stabilizing medium. By this we overcome the deleterious influence of the yolk granules in the isolation procedure. From 11 of Xenopus laevis eggs 25 mg VB-paracrystals can be obtained. The apparent molecular weight of the purified tubulin is 52,800. Antiserum against the purified Xenopus VB-paracrystals, raised in 2 Chinchilla rabbits, cross-reacts in immunodiffusion tests in agar gels with rat brain tubulin and with tubulin isolated from Xenopus laevis eggs by the described procedure. Specific indirect fluorescence staining and appropriate control reactions reveal that cilia of Tetrahymena pyriformis, cytoplasmic networks in cultured mouse Leydig cells, as well as mitotic spindles and nuclear regions in paraffin sections of Xenopus laevis blastulae, react with the antibodies against Xenopus laevis egg tubulin as well as with monoclonal antibodies against pig brain tubulin. These results provide additional evidence for the view that tubulin antibodies are neither species nor tissue specific and show that under appropriate conditions tubulin containing structures can be visualized in paraffin sections.