TABLE 2.

Molecules that were not detected in mouse brain capillaries and their limit of quantification

P-gp was not detected in P-gp and P-gp/Bcrp knockout mice, and Bcrp was not detected in Bcrp and P-gp/Bcrp knockout mice. The other molecules were not detected in any samples. The limit of quantification was calculated as described previously (Uchida et al., 2011). In brief, the limit of quantification was defined as the protein expression level that would give a peak area count of 5000 in the chromatogram when the brain capillary sample was measured in LC/MS/MS.

Molecular Names	Limit of Quantification
	fmol/μg protein
Abca2	0.178
Mdr1a (Abcb1a)	0.135
Mdr1b (Abcb1b)	0.0810
Mrp1 (Abcc1)	0.111
Mrp2 (Abcc2)	3.28
Mrp3 (Abcc3)	0.0570
Mrp5 (Abcc5)	0.136
Mrp6 (Abcc6)	0.118
Bcrp (Abcg2)	0.0390
Mrp7 (Abcc7)	0.253
Pmat	0.0467
Rlip76	0.195