Developing a Clinical-Grade Cryopreservation Protocol for Human Testicular Tissue and Cells

Table 2

Number of viable cells per gram of tissue and recovery of cryopreserved cells.

Patient	Viable cells per gram of tissue			Percent Recovery
	Fresh cells	Frozen cells	Frozen tissue	Frozen cells	Frozen tissue
1	15,300,000	4,057,018	6,630,259	26.5%	43.3%
2	42,800,000	13,312,147	32,958,482	31.1%	77.0%
3	26,900,000	4,114,322	17,889,704	15.3%	66.5%
4	68,624,368	21,006,944	11,224,466	30.6%	16.4%
5	58,877,485	27,549,020	10,704,884	46.8%	18.2%
Average	42,500,371	14,007,890	15,881,559	33.0%	37.4%
SEM	9,313,258	4,390,103	4,390,059	4.8%	11.7%

The number of cells calculated per gram of tissue is compared between isolating cells from fresh tissue, cryopreserved cells, and cryopreserved tissue. For fresh cells, the weight of the tissue of each enzymatic digestion was determined. For frozen cells, the number of cells recovered from each frozen vial was used to calculate how many cells would have been recovered had the cells from 1 gram of tissue been frozen. For frozen tissue, the number of cells isolated from each piece after thawing was used in conjunction with the weight of the tissue before freezing. For all three, only viable cells were used for the calculations. Cell recovery was calculated by dividing the number of viable cells per gram of tissue from either the cryopreserved cell or cryopreserved tissue with the viable cells from fresh tissue cell isolation.