A Corning study showed that half of U.S. scientists did not test for "Mycoplasma" contamination in their cell cultures. The study also stated that, in former Czechoslovakia, 100% of cell cultures that were not routinely tested were contaminated while only 2% of those routinely tested were contaminated (study p. 6). Since the U.S. contamination rate was based on a study of companies that routinely checked for "Mycoplasma", the actual contamination rate may be higher. European contamination rates are higher and that of other countries are higher still (up to 80% of Japanese cell cultures).