What is the difference between spatial proteomics and spatial transcriptomics?

Spatial Proteomics and Spatial Transcriptomics are key technologies in the field of Spatial Omics. Their core objective is to analyze the molecular distribution within cells and tissues from a spatial dimension, focusing on different types of biomolecules and technological approaches.

1. Definition and Research Subjects

Dimension	Spatial Proteomics	Spatial Transcriptomics
Definition	Identifying and quantifying the expression and distribution of proteins within a spatial context of tissues	Capturing and sequencing mRNA in tissue sections in situ to map the spatial patterns of gene expression
Research Subjects	Proteins (functional executors)	mRNA (intermediate product of gene expression)

In brief：

• Spatial Proteomics reveals 'what cells are doing at specific locations';

• Spatial Transcriptomics reveals 'what cells are preparing to do at specific locations'.

2. Technical Principles and Methods

1. Spatial Proteomics

(1) Antibody-based methods：

• Such as CODEX, MIBI, IMC (Imaging Mass Cytometry);

• Using metal-labeled antibodies for tissue staining, followed by identifying multiple protein signals through imaging mass spectrometry and other techniques.

(2) Mass spectrometry imaging methods：

• MALDI-MSI、timsTOF fleX；

• No need for antibodies, directly detecting proteins/peptides on tissue sections for spatial localization.

(3) Laser microdissection and mass spectrometry：

• Using laser microdissection to cut specific areas, extract proteins, and perform quantitative analysis using LC-MS/MS.

2. Spatial Transcriptomics

(1) In situ capture methods (mainstream):

• Such as 10x Genomics Visium, Slide-seq, Stereo-seq;

• Primers arrays are pre-fabricated on the slide surface to capture mRNA in tissues in situ, combining sequencing to obtain spatial coordinates.

(2) In situ hybridization methods：

• Such as MERFISH, seqFISH+;

• Using fluorescent probes targeting specific mRNA to achieve spatial distribution analysis through multiple rounds of imaging.

3. Resolution and Throughput

Parameters	Spatial Proteomics	Spatial Transcriptomics
Resolution	High (from nanometer to single-cell level, depending on the method)	Ranging from cell cluster level to subcellular level
Analytical Throughput	Limited protein types (typically dozens to hundreds)	High mRNA types (up to tens of thousands of genes)

Explanation:

• Spatial Proteomics is limited by antibody types or mass spectrometry recognition capability, resulting in relatively low throughput;

• Spatial Transcriptomics can cover the entire transcriptome, but requires a trade-off in spatial resolution.

4. Advantages and Limitations

1. Spatial Proteomics

(1) Advantages:

• Directly detects functional executors, results are closer to biological phenotypes;

• Independent of transcription levels, can capture post-translational regulation and modifications.

(2) Limitations:

• Technical throughput is limited (especially antibody-dependent methods);

• Lack of unified standards, complex data processing.

2. Spatial Transcriptomics

(1) Advantages:

• High throughput and wide coverage, suitable for constructing spatial cell maps.

• Highly compatible with single-cell RNA sequencing, enabling integrated analysis.

(2) Limitations:

• mRNA expression does not equate to protein expression, potential expression bias may exist.

• Difficult to achieve both spatial resolution and coverage.

V. Comparison of Practical Application Scenarios

Application Directions	Spatial Proteomics	Spatial Transcriptomics
Tumor Microenvironment Studies	Precise localization of immune cell protein expression	Construction of spatial maps of tumor heterogeneity
Drug Target Validation	Observe spatial expression of drug target proteins	Indirect reflection, only for preliminary screening
Neuroscience	Spatial localization of neurotransmitters and receptors	Transcriptional activity maps of different brain regions
Tissue Development Research	Technology is still developing	Distinguish spatial expression dynamics during developmental processes
Clinical Translation	Can be combined with IHC/mass spectrometry to aid diagnosis	Translation paths are still being explored

Although spatial proteomics and spatial transcriptomics have their respective advantages and limitations, they are not substitutes for each other but rather complementary. More and more research is attempting to integrate the two to build Spatial Multi-Omics platforms, achieving a more comprehensive and precise interpretation of tissue microenvironments. At Biotech Pack Biotech, we offer full-process solutions covering spatial proteomics, spatial transcriptomics, and spatial metabolomics, leveraging advanced imaging mass spectrometry and high-resolution single-cell technology platforms to help clients achieve precise analysis from tissue to molecule, from maps to mechanisms, widely applicable in tumor, immune, neurological, and metabolic research fields. Contact Biotech Pack Biotech for customized experimental plans and data analysis services!