PharmaStem Therapeutics has remarkable fundamental patent claims relating to cryogenic preservation of stem cell rich blood. For example, claim 1 of 6,461,645:

1. A cryopreserved pharmaceutical composition comprising:
(a) viable human neonatal or fetal hematopoietic stem cells derived from the umbilical cord blood or placental blood of a single human collected at the birth of said human, in which said cells are present in an amount sufficient to effect hematopoietic reconstitution of a human adult;
(b) an amount of cryopreservative sufficient for cryopreservation of said cells; and
(c) a pharmaceutically acceptable carrier.

Recent reexamination requests relating to two of PharmaStem's patents were blown off - the Patent Office stated that the prior art cited by did not raise a new question of patentability. "I am gratified that the Patent Office reached an early and positive conclusion regarding the key claims in Patents 6,461,645 and 6,569,427," said Nicholas Didier, CEO and President of PharmaStem.