Table 3.

Comparison of the Three Different Spectroscopy Techniques for Measuring Lactate, Glucose, and Ammonium Concentration in Cell Culture Supernatant.

Technology	Model building method	Latent variables	RMSEC (g·L−1)	RMSECV (g·L−1)	${\mathrm{R}}_{\text{C}}^2$	${\mathrm{R}}_{\text{CV}}^2$	Precision (g·L−1)
Lactate concentration
2D‐Fluorescence	Unfolded PLS	9	0.65	1.06	0.975	0.935	0.43
Raman	PLS	6	0.86	1.11	0.957	0.927	0.29
NIR	PLS	9	1.51	2.33	0.868	0.686	0.79
Glucose concentration
2D‐Fluorescence	Unfolded PLS	4	1.36	1.53	0.560	0.442	0.17
Raman	PLS	8	0.46	0.92	0.949	0.798	0.31
NIR	PLS	7	1.09	1.53	0.717	0.452	0.51
Ammonium concentration
2D‐Fluorescence	Unfolded PLS	9	0.021	0.031	0.960	0.917	0.015
Raman	PLS	5	0.064	0.072	0.636	0.533	0.023
NIR	PLS	3	0.087	0.093	0.304	0.218	0.012