Studies on neutron activation analysis for the measurement of sodium in nails as a screening test for cystic fibrosis.

The present study points out the simplicity and ease of using fingernails 
and toenails to measure electrolyte levels as a test for cystic 
fibrosis. Procedures and various effects on the ranges of values for 
different categories of healthy and diseased subjects are discussed and the 
limitations of the method are indicated. 