Caseyn or Casein: How To spell?

The word Caseyn is misspelled against Casein, a noun meaning "A proteid substance present in both the animal and the vegetable kingdom. In the animal kingdom it is chiefly found in milk, and constitutes the main part of the curd separated by rennet; in the vegetable kingdom it is found more or less abundantly in the seeds of leguminous plants. Its reactions resemble those of alkali albumin."

Word contains consecutive vowels 'EI' in between alphabets cas & n is misspelled as 'EY'
Wrong Spelling:  cas-ey-n 
Correct Spelling:  cas-ei-n 
Explore spell check of Casein to spell without errors.