Patent ID: 9295543
Filing Date: 2016-03-29
CPC Classification: A61F,C12N

Claim Text:
1. A method for forming a skin equivalent for application to a human subject comprising: a) providing human product cells, wherein said product cells are near-diploid human keratinocyte (NIKS) cells, providing feeder layer cells, and an agent that prevents cellular replication; b) treating said feeder layer cells with said agent that prevents cellular replication to provide replication inactive feeder layer cells; c) assaying said replication inactive feeder layer cells for replication, wherein said assay comprises plating said replication inactive feeder layer cells at a density of from about 7,810 to about 15,630 cells/cm d) cryopreserving said replication inactive feeder layer cells; e) thawing said replication inactive feeder layer cells to provide thawed replication inactive feeder layer cells; f) culturing said product cells on said thawed replication inactive feeder layer cells; g) separating said product cells and said thawed replication inactive feeder layer cells; h) assaying a representative portion said product cells for the presence of feeder layer cell DNA; i) selecting product cells harvested from a feeder layer for which said representative portion of said product cells contain less than 0.015% feeder cell DNA equivalents within the total cell population; and j) forming a skin equivalent from said product cells, and k) assaying said skin equivalent for feeder cell DNA and discarding skin equivalents having more than 1.45×10