A Simplified Ultra-Micro Kjeldahl Method for the Estimation of Protein and Total Nitrogen in Fluid Samples. of Less Than 1·0μ1

ABSTRACT An ultra-micro modification of the Kjeldahl method is described whereby nitrogen can be estimated in a blood sample of less than 1 μl. Volume. This is simpler than previously described methods as regards apparatus and procedure. The separate estimations of protein and total nitrogen are also introduced. For samples containing 1·0-10·0 μg. N the standard deviation is 0·02-0·04 μg. N. Preliminary tests indicate that for 0·1-1·0 μg. N the standard deviation would be of the order of 0·006-0·008 μg. N.