The lipid family is large, with similar structures but very different functions. Taking the DPI case as an example, positive ion mode can present choline, phosphocholine, PC lipids, sphingomyelin SM, cholesterol and various neutral GalCer lipids; negative ion mode can present phosphatidylethanolamine PE, plasmalogen PE-O, phosphatidylserine PS, phosphatidylinositol PI, sulfatide ST, etc. The spatial distribution of different lipids directly reflects membrane structure, signaling state and metabolic activity.
In neuroscience and tumor research, lipid imaging is especially valuable: mouse brain sections can simultaneously image neurotransmitters and various lipids, guiding neuroscience, pharmacology and neurochemistry; in the melanocytic nevus case, the nevus region and normal tissue showed systematic differences in non-polar lipids such as MAG/DAG/TG and in S1P, cholesterol, PC and SM.
Lipids span a wide polarity range, from strongly polar phospholipids to completely non-polar triglycerides and cholesterol. Traditional DESI has polarity bias against non-polar components and strong ion suppression; the Neo-Source MSI DPI, through desorption electrospray ionization combined with photochemical post-ionization, has no polarity bias, simultaneously covering polar and non-polar lipids, with overall metabolite signal enhanced by 1–3 orders of magnitude and significantly improved detection of non-polar components.
Published quantitative cases show that cholesterol signal in mouse brain increased by about 205x; in negative ion mode PE-O/PE signal increased by 2–4x. These data intuitively reflect the sensitivity leap of photoionization for lipids.
Lipid distribution can be registered with pathological structures: in the DPI melanocytic nevus study, the specific distributions of S1P, cholesterol, PC34:1 and PC38:4 highly matched the H&E nevus region and cholesterol aggregation in the nevus was verified by IHC, suggesting lipids participate in nevus formation (Talanta, 2021). In the neuroscience direction, co-imaging of neurotransmitters and lipids provides molecular spatial evidence for neurochemistry and pharmacological research.
Matrix-free preparation makes such lipid studies, which often require many sample comparisons, easier to deploy: the two Neo-Source imaging sources are matrix-free and measure on demand, and the section remains intact after imaging for continued H&E or IHC validation.
DPI's 20–200 μm resolution can depict lipid partitions of organs and local lesions; for entering single-cell/subcellular scale (e.g., judging whether lipids localize to a specific organelle or cell band), the Neo-Source MSI LDPI provides 2–3 μm matrix-free ambient imaging as a supplement.
DPI is engineered to be compatible with mainstream mass spectrometers from Agilent, AB SCIEX and Thermo. It provides a self-developed titanium-alloy ion transfer tube that does not damage the sample at the front end and is detachable for cleaning, enabling stable and reproducible lipid imaging, and it can be combined with spatial metabolomics and spatial proteomics for multi-omics integration.
To obtain detailed specifications, compatible models, or a quotation for the MSI LDPI / DPI full series imaging ion sources, visit the Neo-Source official website, or contact the official team for compatibility advice tailored to your mass spectrometer (Agilent / SCIEX / Thermo and other mainstream MS).