Reclaiming the "Lost Spatial Coordinates": Break Single-Cell Limits and Unlock Spatiotemporal Insights with SDAS

07/08/2026

1. What is SDAS

SDAS (Spatial Data Analysis Software) is an "out-of-the-box, unzip-and-run" Linux command-line analysis toolkit developed by BGI STOmics for Stereo-seq spatiotemporal data. SDAS covers the entire analysis workflow from raw data preprocessing to figure output. Researchers no longer need to manually stitch together various scripts and tools — they can complete standardized, high-quality spatial omics analysis right away. SDAS also comes with a companion Analysis Guide and an advanced spatial analysis Pipeline.

  • SDAS Toolkit: 14 analysis modules and 31 hand-picked, benchmark-validated algorithms. Modules are called via the command line, expose key parameters, and can be used independently or in combination.

  • Analysis Guide (Algorithm Benchmarking Column): For common spatial omics analysis tasks (cell type annotation, spatial co-expression, etc.), we benchmark algorithms across four dimensions — algorithm principles, parameter effects, computational resources, and results — and provide practical recommendations based on Stereo-seq data.

  • Advanced Spatial Analysis Pipeline: Chains SDAS modules into an executable Python workflow that follows a typical research logic. Comes with example data and a conf configuration file — no Snakemake / Nextflow required.

In short, the Analysis Guide answers "why use this algorithm," the SDAS Toolkit answers "how to use it," and the Pipeline answers "in what order to use it."


2. What Problems SDAS Solves

Through our conversations with research groups, we've noticed that spatial transcriptomics analysis commonly runs into three practical issues.

Limited analytical thinking. The most common scenario: after getting spatial data, researchers still follow the single-cell playbook — dimensionality reduction, clustering, differential expression, pathway enrichment. But these steps were already done at the scRNA-seq stage. Without analyses that leverage spatial coordinates, the final figures never actually show "where the cells sit in the tissue." The results end up looking no different from single-cell output, and the premium paid for the spatial experiment is hard to justify.

High cost of algorithm selection. For cell type annotation alone, the community offers many mainstream methods — cell2location, RCTD, Tangram, and more — with wide differences in accuracy, runtime, reference-set requirements, and GPU memory usage. Most researchers pick algorithms based on citation counts or in-group experience, without evidence tested on Stereo-seq data. Within a typical project cycle, they can usually only try 1–2 methods.

Time-consuming environment setup. cell2location's PyTorch dependencies conflict with Scanpy; CellChat's R packages don't match SeuratWrappers versions; different algorithms require different CUDA versions. Manually configuring a full spatial analysis stack usually takes 1–2 weeks — most of it spent troubleshooting the environment instead of doing analysis.


3. The SDAS Toolkit

3.1 Highlights

  • End-to-end coverage: A single tool that integrates 31 mainstream algorithms in the spatial transcriptomics field, wrapped into 14 analysis modules covering everything from raw data preprocessing to figure output.

  • Simple installation: On Linux, just unzip and use. All required dependencies are bundled and pre-compiled — no need to separately configure Python, R, CUDA, or any other complex dependency environments.

  • Ecosystem compatibility: Directly reads .h5ad / .h5mu output from STOmics' SAW analysis software, or works with AnnData / Seurat data prepared according to the user manual.

3.2 Overview of the 14 Analysis Modules

Regular single-cell transcriptomics tells you "which cell types are present and what genes they express" — but it loses the critical dimension of "where the cells are." Spatial transcriptomics keeps every piece of information single-cell gives you and additionally provides "spatial coordinates," unlocking a whole range of analyses that single-cell simply cannot do. The table below lists the full functionality of all 14 modules, and whether each module's chosen algorithm supports single-cell data as well or is spatial-only.

Module

Function / Biological Meaning

Applicability

Data Preprocessing

Reads SAW output and h5ad files; supports multi-slice merging, format conversion, information printing, subset extraction, etc.

Single-cell / Spatial

Cell Type Annotation (non-clustering)

*Integrates spatial-omics-specific methods

Decodes the mixed signal at each in-situ spot and precisely reconstructs which cell types compose each spot and in what proportions.

Spatial-only

Spatial Domain Identification

Combines gene expression with spatial position to automatically delineate tissue microregions with specific functional or pathological features.

Spatial-only

Spatial Gene Co-expression

Finds gene modules that are jointly upregulated in space, revealing functional coordination within local tissue regions.

Spatial-only

Cell Neighborhood Analysis

Uncovers the "microenvironmental niche" surrounding each cell, revealing the cellular composition patterns of local pathological microenvironments.

Spatial-only

Cell Spatial Distance

Quantifies the real physical distances between different cell types, assessing spatial co-localization or physical exclusion tendencies between cells.

Spatial-only

Cell Communication (with spatial constraints)

Under real spatial distance constraints, accurately predicts ligand–receptor signaling between spatially neighboring cells.

Spatial-only

CNV Analysis

Infers chromosomal copy number variation from gene expression and identifies tumor vs. normal cells with high precision directly on the tissue section.

Single-cell / Spatial

Differential Gene Analysis

Discovers key molecular markers specifically expressed across different tissue regions, pathological grades, or cell populations.

Single-cell / Spatial

Gene Set Enrichment Analysis

Maps differential molecules to known biological pathways, quickly explaining the active cellular functions and metabolic states in the region.

Single-cell / Spatial

Trajectory Analysis

Infers how gene expression evolves across the tissue's physical space, simulating the dynamic process of cell differentiation or disease progression.

Single-cell / Spatial

Transcription Factor Analysis

Identifies "master" transcription factors that control specific spatial regions or cell states, along with their downstream gene networks.

Single-cell / Spatial

Protein–Protein Interaction Network

Maps key genes onto protein interaction networks to pinpoint core protein nodes driving pathological phenotypes.

Single-cell / Spatial

Public Database Validation

Feeds genes or cellular features discovered from spatial data into large clinical cohorts such as TCGA to validate their prognostic and diagnostic value.

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3.3 Module Algorithm List

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4. Case Study: Tertiary Lymphoid Structure (TLS) Analysis in CRC

Using Stereo-seq bin20 data from a colorectal cancer (CRC) sample as an example, we show how SDAS identifies tertiary lymphoid structures (TLS) in tumor tissue and explores the link between TLS and tumor prognosis.

4.1 Advanced Spatial Analysis Pipeline Workflow

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4.2 Key Steps and Findings

Step

Biological Meaning

Annotation

Building the cell atlas: identified immune subpopulations including B cells and T cells

Co-expression

Identifying and validating TLS structure: found 3 modules correlated with TLS spatial patterns, and 18 genes among the TLS_50 marker genes

Neighborhood

Tumor microenvironment: 5 CNs — Epi-enriched, immune-enriched, Fibro/smooth muscle, Plasma, Endo

DEG + Enrichment

Genes and pathways: in CN2 (the immune region), complement pathway and inflammatory response were upregulated; EMT and glycolysis were downregulated

CCI

Cell–cell interactions: B-T-NK-ILC-Myeloid communication was enhanced in CN2; CD86-CD28 was significant in DC→T signaling

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5. Algorithm Benchmarking Column

To help researchers make independent methodological choices beyond SDAS, we've launched an algorithm benchmarking column around mainstream spatial omics algorithms, structured as "theory + benchmark + recommendation." Two issues have been published so far:

5.1 Cell Annotation Algorithm Benchmark

Compares methods such as cell2location, RCTD, SPOTlight, Tangram, and SCimilarity on Stereo-seq data across different tissue types and resolutions, evaluating both accuracy and resource consumption.

5.2 Spatial Gene Co-expression Algorithm Benchmark

Compares methods such as Hotspot, hdWGCNA, and NeST on Stereo-seq data across different tissue types and resolutions, evaluating both accuracy and resource consumption.


6. Download and Usage

6.1 SDAS Installation Package and Pipeline

6.2 SDAS User Manual