Table 1.
Matrix effects on the results of direct tissue SALDI MSI and iMSI detection of different lipid standards in different brain regions.
| Approach | Region | [CEr+Na]+ (m/z 588.5) | [CEr+K]+ (m/z 604.5) | [PE+Na]+ (m/z 750.6) | [PE+K]+ (m/z 766.6) | [CB+Na]+ (m/z 850.6) | [CB+K]+ (m/z 866.6) |
|---|---|---|---|---|---|---|---|
| Direct tissue SALDI MSI | CTX | 18± 8 | 1330±670 | 0.34±0.08 | 53±25 | 85±47 | 1230±750 |
| CC | 7±3 | 320± 140 | 17±5 | 455±50 | 326±50 | 6490±1300 | |
| CA1 | 11±8 | 475±367 | 44 ±14 | 212±121 | 264±183 | 4560±3700 | |
| CA3 | 46±17 | 890±370 | 1.3 ±0. 3 | 0.11± 0.03 | 0.10±0.03 | 28±6 | |
| iMSI | CTX | 76±32 | 67±30 | 7±3 | 10±3 | 33±8 | 11±3 |
| CC | 84±11 | 43±26 | 12±6 | 16±6 | 124±25 | 12±6 | |
| CA1 | 89±18 | 29±52 | 21±16 | 27±6 | 51±6 | 34±12 | |
| CA3 | 32±33 | 5±3 | 10±5 | 16±3 | 46±17 | 20±7 |
CTX, cortex; CC, corpus callosum; CA1, region I of hippocampus proper; CA3, region III of hippocampus proper; Cer, ceramide; PE, phosphatidylethanolamine; CB, cerebroside. Mean ± standard deviations for all points/pixels were assessed. Matrix effects determined as ratios of lipid standard signal areas determined by measurements of arrays of microspots deposited onto (1) tissue slices and clean ITO glass surfaces (SALDI MSI) (n=2 animals); (2) tissue imprints and clean ITO glass slides coated with TiO2-DA monolith (iMSI) (n=2 animals).