What is no longer possible now that Grandfather's tissue samples have been lost?

Cassia loves her grandfather very much, and her solace in his death was the fact that he would be resurrected once again thanks to the tissue samples. They would all be together when scientists figured out how, and she firmly believed that someday the scientists would do this. When she finds out that her father has lost her grandfather's tissue samples, the idea of death is very final to her. She doesn't know how to assimilate this information.