A Method for Measuring Acid Mucopolysaccharides in Serum-containing Tissue Culture Media’

changed, whereas hexosamine values were gradually increased and seemed to be correlated to total cell count, but not to the count of adhered cells on the glass wall. On the other hand, hexosamine and sialic acid contents of both the cells adhering to the glass wall were determined after washing with saline solution. The results are given in Table I. No remarkable difference in hexosamine and sialic acid contents was found between the cells. The results show that no sialic acid-containing substance is accumulated in the media during the growth of tumor cells. This fact may give some support to the opinion that the increased sialic acid content of serum in tumor-bearing animals, as well as in patients, is not due to a production of sialoproteins in the tumor. In our laboratory it was also found that the cells of the C3H ascitic hepatomas do not show a higher level of hexosamine or sialic acid than the levels of normal liver cells of C3H mice [5]. As to the origin of an increased serum level of sialic acid in tumor-bearing animals further experiments are necessary.