Microscopic tests for amino acids

Summary

1. The amino acids were found to react with the alkaloid reagents and solutions of salts of the heavy metals giving distinctive types of crystals that may be used as a means for their identification.

2. Less than 5 milligrams of the amino acids are required for such a test.

3. Cystine and tyrosine were isolated and identified by such tests.

4. A systematic scheme of analysis might be developed for the identification of the amino acids by dividing them into natural groups according to their solubilities and sensitivity toward the various reagents.

The authors wish to acknowledge the assistance ofM. L. Shaner in checking the tests and reading the manuscript.