Table 3.

Particle sizes and concentrations determined by NTA (second round)

	L2.1	L2.2	L2.3	L2.4 Cv, %	p value
Median diameter, nm	156.9±8.6	151.5±23.7	134.6±18.3	128.7±17.7	9.38	0.0215
Particles per mL CCM	7.50×108±8.05×107	4.15×108±2.68×108	3.12×108±2.21×108	4.12×108±1.22×108	40.49	0.0023

All data are mean ± SD of replicate measurement within one laboratory. CCM, cell-conditioned medium.