HA synthesis by human HPCs.

HA synthesis by CB CD34⁺CD38⁻ cells following 60 hours in culture demonstrated using Superose 12 size exclusion chromatography by the difference in [³H] counts eluted at fractions 15 to 25 before digestion withStreptomyces hyaluronidase (○) versus total digestion of high-molecular-weight material to the enzymatic degradation products tetrasaccharides and hexasaccharides (●). The 3 peaks represent HA within the cell supernatant. The molecular weights of synthesized HA were determined by comparison with eluted purified HA of known molecular size. For calculation of recovery, counts were taken as significant when they were more than 3 SDs above the mean background (n = 15).