Sialic acids. I. Technic of the quantitative determination of N-acetyl-neuraminic acid in human serum and its normal values

Abstract

A technique based on Svennerholm's cupric-resorcinol me- thod for N-acetylneuraminic acid (Nana) determination in hu­ man serum is detailed.

Heating conditions have been 108° C ± 0,5 during 11 mi­ nutes. Instead of using amyl alcohol-as extracting liquid, butylacétate has been used, according to Miettinen and coll.’s advi- ce, which permits the final separation of the resulting two layers without centrifuging.

Nana valúes in adults normal sera (22 to 27 yrs) have been : 60 ± 10,4 mg. for 100 mi. serum; and for children (4 mths to 2 yrs) : 64,4 ± 7,4.

These valúes agree fairly with results published bj1, others (Table I).

In the same normal subject a large variability has been noti- ced according to different days (Fig. 1).