Table 3.

Mitochondrial membrane potential of U937 cells after the freezing - thawing cycle.

TMRM fluorescence signal	The devices used for FTC			P
	i3C	mini-vial	standard cryo-vial
mean FI (au)	726 ± 578.8	754.5 ± 690.8	814.8 ± 534.4	0.9
FI SD (au)	532.8 ± 327.5	455 ± 332.3	624.5 ± 365.6	0.8

U937 cells underwent a freezing - thawing cycle in appropriate cryo-devices and 1.5 hours after thawing cells were stained by TMRM as described in Materials and Methods. Mean FI and FI SD values were measured by Image Analysis in each individual cell. The average mean and SD for each measured parameter were calculated for the different cell populations under investigation (controls and experiments) as described in Statistical analysis.Values are average ± SD of each group of cryo-devices.