Table 8. Collective PLS-DA Models for All SERS and FT-IR Spectra, Calibrated by Sex for PBA (A), PBU (B), SBA (C), and SBU (D)^a.

		SERS	actual sex		FT-IR	actual sex
	predicted sex	accuracy, %	female (n = 250)	male (n = 250)	accuracy, %	female (n = 15)	male (n = 15)
A	female	97.2	243	2	86.7	13	2
	male	99.2	7	248	86.7	2	13
	MCC = 0.964				MCC = 0.733
B	female	98.8	247	3	86.7	13	3
	male	98.8	3	247	80.0	2	12
	MCC = 0.976				MCC = 0.668
C	female	95.2	238	12	80.0	12	1
	male	95.2	12	238	93.3	3	14
	MCC = 0.904				MCC = 0.740
D	female	97.6	244	11	93.3	14	1
	male	95.6	6	239	93.3	1	14
	MCC = 0.932				MCC = 0.867

^aMatthew’s correlation coefficient (MCC) indicates the level of reliability between binary classifications.