Abstract
1) The method for determination of betaine, devised by FRIEDMAN et al., was found to be not applicable to the samples, which are abundant in proline, as it moves almost as fast as betaine in the column of Dowex 50.
2) The original method was modified by adding a procedure to remove proline from the betaine fraction with the column of Amberlite IRA-400.
3) The amount of betaine in the muscle of some marine invertebrate animals, such as squid, octopus, hard clam and prawn, was estimated by the modified method.
4) These tissues revealed a very high content of betaine, indicating that it is one of the main nitrogenous constituents in the muscle extracts of these animals.
The authors are indebted to Prof. Y. HASHIMOTO for his kind advice. The expenses of this investigation were defrayed in part by a research fund granted from the Ministry of Education.
