Table 1.

Output Accuracy of the Different Viability Assays

	CellTiter-3D		CellTiter-2D		Presto Blue		MTS
	Slope	R2	Slope	R2	Slope	R2	Slope	R2
Collagen
10 μL	3.813E-05	0.9940	3.661E-05	0.9898	1.613E-05	0.9930	1.922E-05	0.9301
25 μL	2.758E-05	0.9967	2.048E-05	0.9862	2.211E-05	0.9617	2.120E-05	0.9730
50 μL	2.798E-05	0.9979	1.934E-05	0.9758	2.259E-05	0.9512	2.813E-05	0.9157
100 μL	2.836E-05	0.9877	1.418E-05	0.9995	2.215E-05	0.9404	2.421E-05	0.9381
HA:collagen
10 μL	5.752E-05	0.9833	3.137E-05	0.9994	3.137E-05	0.9910	2.655E-05	0.9997
25 μL	3.863E-05	0.9970	3.391E-05	0.9561	3.391E-05	0.9945	4.057E-05	0.9736
50 μL	4.598E-05	0.9954	3.999E-05	0.9735	3.999E-05	0.9825	6.027E-05	0.9725
100 μL	8.225E-05	0.9486	7.851E-05	0.9996	7.851E-05	0.9468	1.208E-04	0.9908
HyStem®
10 μL	1.927E-05	0.9743	1.236E-05	0.9046	1.619E-05	0.9999	1.364E-05	0.9910
25 μL	2.226E-05	0.9954	1.978E-05	0.9662	1.813E-05	0.9827	2.683E-05	0.9443
50 μL	3.049E-05	0.9843	2.012E-05	0.9728	3.220E-05	0.9999	4.066E-05	0.9866
100 μL	2.141E-05	0.9976	2.435E-05	0.9189	5.052E-05	0.9992	1.269E-05	0.8287

The slope and R² values of the linear regression for each viability assay was calculated in Microsoft Excel in different of hydrogel formulations, as indicated. Slope values within 50% of the theoretical slope, ranging from 2.5E-05 to 7.5E-05, are highlighted in italics. The R² values that are ≥0.99 are highlighted in bold. These values were picked to help visually interpret the data.

2D, two-dimensional; 3D, three-dimensional; HA, hyaluronic acid.