How to choose between ambient and vacuum sources (MALDI/SIMS)?

For simplified preparation, near-in-situ analysis and small-molecule low background, choose an ambient matrix-free source (LDPI/DPI/DESI); for proteins/peptides or an extremely clean background, choose vacuum MALDI/SIMS.

Does ambient imaging require a matrix?

DESI, LDPI and DPI require no organic matrix; AP-MALDI still requires a matrix but operates under ambient pressure.

Is Neo-Source LDPI an ambient matrix-free source?

Yes. LDPI works in an open ambient environment, requires no matrix spraying, has a low background above m/z≥70, and is suitable for drug and metabolite imaging.

Product · Neo-Source

Ambient MSI Ion Source

Ambient MSI ion sources directly ionize the sample surface point by point in an open atmospheric environment, without placing the sample in a vacuum chamber. DESI, LDPI, DPI and AP-MALDI all belong to this category; their core value lies in simplifying sample preparation, supporting near-in-situ analysis, and reducing dependence on large vacuum systems.

Table of Contents
1. Working principle and typical routes 2. Sample preparation and applicable scenarios 3. Neo-Source LDPI/DPI ambient solution

Ambient MSI Ion Source — schematic diagram

1. Working principle and typical routes

Ambient imaging sources operate at atmospheric pressure: DESI uses charged droplets that impact the surface for desorption and ionization; LDPI excites the sample with a laser and then ionizes the neutral desorbed species photochemically; DPI combines electrospray with photoionization in a synergistic manner; AP-MALDI moves the matrix-assisted desorption of conventional MALDI to ambient pressure. Their common feature is that the sample need not enter vacuum, so colored, aqueous or large-volume samples can be analyzed directly.

By eliminating vacuum pumping and complex sample transfer, ambient sources have structural advantages in sample throughput, operational convenience, and in-vivo/near-in-situ research. The trade-off is the need to control air background and humidity, and to efficiently introduce ambient ions into the mass analyzer through an interface.

2. Sample preparation and applicable scenarios

Compared with vacuum MALDI/SIMS, which require frozen sections, conductive slides and spraying, the ambient matrix-free route (LDPI/DPI) usually only requires placing the sample on a positioning stage and calibrating coordinates, significantly reducing the preparation steps, and is especially suitable for time-sensitive scenarios such as clinical rapid sections, in-situ analysis of medicinal materials, and forensic evidence.

In application, ambient sources excel at the tissue distribution of metabolites, lipids, drugs and their metabolites; for macromolecules such as proteins/peptides, matrix or higher-vacuum strategies are still required. Choosing ambient or vacuum essentially comes down to a trade-off between simplified sample preparation and macromolecule coverage or clean background.

3. Neo-Source LDPI/DPI ambient solution

Neo-Source MSI LDPI is an ambient, matrix-free, laser/photoionization imaging source with a spatial resolution of 2–3 μm (among the leading in the industry), a low background above m/z≥70, and is suitable for imaging small-molecule drugs and metabolites; MSI DPI uses electrospray plus photoionization to achieve no polarity bias, with a nominal sensitivity 1–4 orders of magnitude higher than DESI, covering tissue-scale imaging of 20–200 μm.

Both adopt an external modular design compatible with mainstream mass spectrometers such as Agilent, SCIEX and Thermo, allowing users to gain ambient matrix-free imaging capability while retaining their original instrument investment.

Neo-Source MSI LDPI Laser Desorption Photoionization Imaging Source

Matrix-free:No organic matrix spraying required; m/z>=70 low background, well suited to small-molecule drugs and metabolites

Ambient operation:Works in open ambient environment; simplified sample preparation; supports near in-situ / in-vivo analysis

Resolution:2-3 um spatial resolution, among the leading in the industry, reaching single-cell / subcellular scale

Modular compatibility:External add-on design; model-by-model compatibility with Agilent / SCIEX / Thermo mainstream MS hosts

View LDPI specifications and compatible models →

Frequently Asked Questions (FAQ)

What is an ambient MSI ion source?: An imaging ion source that directly ionizes the sample surface point by point in an open atmospheric environment without a vacuum chamber; representative examples are DESI, LDPI, DPI and AP-MALDI.
How to choose between ambient and vacuum sources (MALDI/SIMS)?: For simplified preparation, near-in-situ analysis and small-molecule low background, choose an ambient matrix-free source (LDPI/DPI/DESI); for proteins/peptides or an extremely clean background, choose vacuum MALDI/SIMS.
Does ambient imaging require a matrix?: DESI, LDPI and DPI require no organic matrix; AP-MALDI still requires a matrix but operates under ambient pressure.
Is Neo-Source LDPI an ambient matrix-free source?: Yes. LDPI works in an open ambient environment, requires no matrix spraying, has a low background above m/z≥70, and is suitable for drug and metabolite imaging.

Get Specifications & Quotation

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).

MSI Ion Source DESI Neo-Source MSI LDPI Laser Desorption Photoionization imaging ion source DPI Dual-Photoionization Imaging Source Matrix-Free MSI Ion Source External MSI Ion Source (modular expansion solution)

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