CNSide Diagnostics
CNSide Diagnostics, a Houston-based subsidiary of Plus Therapeutics, operates a CLIA-accredited molecular diagnostics laboratory running the proprietary CNSide CSF Assay Platform to detect and characterize tumor cells in cerebrospinal fluid for neuro-oncologists managing leptomeningeal metastases.
- Company typePrivate
- Founded2024
- HeadquartersHouston, United States
- Headcount11–50
- GTM typeB2B
- OfferingServices
What CNSide Diagnostics does
CNSide Diagnostics is a Houston-based molecular diagnostics company operating as a wholly-owned subsidiary of Plus Therapeutics (NASDAQ:PSTV). The company develops and commercializes the CNSide CSF Assay Platform, a proprietary cerebrospinal fluid assay designed to detect, quantify, and molecularly characterize tumor cells in CSF. Its primary clinical application is the diagnosis and monitoring of leptomeningeal metastases, a serious oncology complication involving spread of disease to the membranes surrounding the brain and spinal cord. The customer base comprises neuro-oncologists, oncologists, NCI-designated cancer centers, and academic medical centers, totaling more than 120 institutional accounts.
The platform combines a proprietary multi-antibody microfluidic cell-capture architecture with the CEE-Sure collection and shipping tube, enabling external sites to ship CSF specimens to CNSide's CLIA-accredited, CAP-accredited Houston laboratory for centralized analysis. CNSide has vertically integrated in-house manufacturing of its collection tubes, antibody mixes, and microfluidic chips, which reduces supply risk and tightens control over pre-analytic quality. The business model is fee-for-service clinical laboratory testing, with billing routed through commercial payers, Medicare, and the dedicated CPT code 0640U.
Following a $15M public offering in January 2026, the achievement of CLIA, CAP, and Medicare regulatory milestones, and a national coverage agreement with Elevance Health, CNSide has expanded operations to roughly 48-50 states with payer reach extending to approximately 126 million covered lives. The company is preparing to broaden its menu with CSF-based ICC, FISH, and NGS assays in 2026 and has signaled intent to expand internationally after U.S. scale is established.
CNSide Diagnostics firmographics
Firmographics- Name
- CNSide Diagnostics
- Legal name
- CNSide Diagnostics, LLC
- Website
- https://cnside-dx.com
- Company type
- Private
- Founded year
- 2024
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- CNSide Diagnostics, a Houston-based subsidiary of Plus Therapeutics, operates a CLIA-accredited molecular diagnostics laboratory running the proprietary CNSide CSF Assay Platform to detect and characterize tumor cells in cerebrospinal fluid for neuro-oncologists managing leptomeningeal metastases.
- Ownership category
- akta.pro rank
CNSide Diagnostics industry classification
Industry- Product category
- Molecular Diagnostics
- NAICS
- Medical Laboratories (621511), In-Vitro Diagnostic Substance Manufacturing (325413), Medical and Diagnostic Laboratories (62151)
- SIC
- Services-Medical Laboratories (8071), In Vitro & In Vivo Diagnostic Substances (2835)
- akta.pro primary industry
- Oncology Diagnostics (tumor profiling, MRD, liquid biopsy) (HLAAALAE)
- akta.pro secondary industries
- Cytology & Histopathology Diagnostics (IHC, ISH, tissue-based assays) (HLAAALAI), Specialty & Biomarker Laboratory Services (Immunoassays/Flow/Cytometry) (HLAGAEAB)
Keywords
Where CNSide Diagnostics is headquartered
LocationHeadquarters
- HQ city
- Houston
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
CNSide Diagnostics business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure
Revenue model
- Laboratory Testing Services: CNSide Diagnostics generates revenue through clinical laboratory testing services. The company bills commercial payers, Medicare, and patients for its CSF tumor cell enumeration test. A new CPT code (0640U) became effective July 1, 2026, enabling standardized billing and claims processing.
- Commercial Payer Agreements: Revenue generated through coverage agreements with commercial health insurers including United Healthcare, Humana, Highmark, Blue Shield of California, and Elevance Health. The company has approximately 126 million total contracted covered lives as of June 2026.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Transaction based/ take rate | Pay-as-you-go | Insurance-based billing through commercial payers and Medicare |
Go-to-market motion2 records
Distribution channels1 record
Marketing channels6 records
CNSide Diagnostics product offering
Product offeringCore offering
CNSide Diagnostics operates a CLIA-certified clinical laboratory that runs the proprietary CNSide® CSF Assay Platform, with the commercially available CNSide® CSF Tumor Cell Enumeration (TCE) test detecting and quantifying tumor cells in cerebrospinal fluid for diagnosing and monitoring leptomeningeal metastases. The company also manufactures the proprietary CEE-Sure® CSF Collection Tube preservative used to stabilize CSF specimens during transport, and is developing molecular characterization tests (ICC, FISH, NGS) on the same CSF sample.
Product overview
CNSide Diagnostics offers the CNSide® Cerebrospinal Fluid (CSF) Assay Platform, a suite of molecular diagnostic tests for detecting and analyzing cancer cells in cerebrospinal fluid. The platform currently includes the commercially available CNSide® CSF Tumor Cell Enumeration (TCE) test, with additional tests in development including CSF ICC, FISH, and NGS tests expected to launch in 2026. The company manufactures key test components including the CEE-Sure® CSF collection tube preservative, antibody mix, and microfluidic chip in-house at its Houston, Texas facility for vertical integration and scalability. The platform enables rapid diagnosis, treatment monitoring, and treatment guidance for patients with leptomeningeal metastases.
Differentiator
Problem solved
Functional benefit
Brands
- CNSide® CSF Assay Platform: A proprietary cerebrospinal fluid assay platform that provides tumor cell enumeration and molecular characterization for managing leptomeningeal metastases and CNS cancers.
- CNSide® CSF Tumor Cell Enumeration (TCE)
Products and services
- CNSide CSF Tumor Cell Enumeration (TCE) Test Clinical laboratory test that detects, quantifies, and reports tumor cells in cerebrospinal fluid using the proprietary CNSide CSF Assay Platform; intended for neuro-oncologists and oncologists diagnosing and monitoring leptomeningeal metastases from solid tumors.
- CEE-Sure CSF Collection Tube Proprietary specimen collection tube containing a preservative that stabilizes cerebrospinal fluid during transport to the CNSide Diagnostics CLIA laboratory, supporting the integrity of the Tumor Cell Enumeration test.
Quantifiable outcome
- 92% sensitivity and 95% specificity for leptomeningeal metastases detection
- +3 more outcomes
Companies that use CNSide Diagnostics
Customer profileNamed customers2 records
Segments3 records
Ideal customer profiles1 record
CNSide Diagnostics technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
CNSide Diagnostics partnerships and signals
Strategic signalPartnerships
One partnership is on record.
- Plus Therapeutics, Inc.coreCNSide Diagnostics, LLC is a wholly-owned subsidiary of Plus Therapeutics, Inc. (NASDAQ: PSTV). Plus Therapeutics acquired all CNSide® assets and established CNSide Diagnostics in 2024. The subsidiary operates independently to commercialize the CNSide CSF Assay Platform while Plus Therapeutics focuses on its radiopharmaceutical pipeline including REYOBIQ.
Scale indicators7 records
Recent moves8 records
Expansion highlights6 records
CNSide Diagnostics competitors and assessment
Company assessmentDirect peers
- Guardant Health: Leading oncology liquid biopsy company with Guardant360 CDx and Guardant Reveal MRD products using cell-free DNA approaches. Most directly comparable peer in the blood-based oncology liquid biopsy category, sharing CNSide's strategy of using rare-cell/DNA analytics to guide solid tumor treatment.
- Personalis: Molecular diagnostics company offering NeXT Personal (tumor-informed MRD) for solid tumors. Direct peer in liquid biopsy MRD and treatment monitoring for oncology, with similar payer coverage focus.
- Biocept: Originally developed and commercialized the CNSide® CSF assay platform beginning in 2020; CNSide Diagnostics was established in 2024 when Plus Therapeutics acquired all CNSide assets from the prior program. Biocept represents the most direct historical predecessor in CSF-based liquid biopsy for oncology.
- Natera: Oncology liquid biopsy peer commercializing Signatera for molecular residual disease (MRD) monitoring and treatment response assessment. Shares CNSide's molecular treatment-monitoring positioning and similar payer-coverage expansion strategy across U.S. oncology.
- Tempus AI: AI-powered precision medicine company offering xT (tissue), xR (liquid biopsy/RNA), and xF (ctDNA) oncology diagnostics. Comparable peer combining molecular profiling with proprietary data/molecular tumor board workflows for academic oncology centers.
- Foundation Medicine: Subsidiary of Roche providing comprehensive genomic profiling (FoundationOne CDx) and liquid biopsy (FoundationOne Liquid CDx) for solid tumors. A direct molecular tumor profiling and liquid biopsy peer with overlapping clinical customers (academic medical centers, oncologists).
- Caris Life Sciences: Molecular profiling company offering MI Profile (tissue) and MI Cancer Seek (blood) for solid tumor molecular characterization and MRD. Directly comparable on molecular tumor profiling and CNS-adjacent cancer applications.
- NeoGenomics: Oncology-focused clinical laboratory and molecular diagnostics company offering comprehensive tumor profiling, including liquid biopsy services. Closely comparable specialty lab operating model with similar payer coverage and academic cancer center customer focus.
Broad incumbents
- Exact Sciences: Larger oncology diagnostics incumbent with Cologuard (screening) and Oncotype DX (tumor profiling), now expanding into MRD via the Thrive acquisition. Comparable on payer contracting scale and commercial U.S. footprint but broader, more diversified than CNSide's leptomeningeal focus.
Emerging players
- Burning Rock Biotech: China-based oncology liquid biopsy company commercializing tumor profiling and MRD assays. Comparable technology and clinical positioning with CNSide, but operating from a different geography and primarily serving the Chinese market.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks7 records
Key highlights7 records
Customer concentration
CNSide Diagnostics social profiles
Digital presenceCNSide Diagnostics compliance and trust
Trust signalCompliance3 records
CNSide Diagnostics financial estimates
Financial estimateRevenue estimate
Valuation estimate
CNSide Diagnostics leadership team
Management profileNumber of profiles
Profiles10 records
CNSide Diagnostics funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
CNSide Diagnostics M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about CNSide Diagnostics
What does CNSide Diagnostics do?
CNSide Diagnostics operates a CLIA-certified clinical laboratory that runs the proprietary CNSide® CSF Assay Platform, with the commercially available CNSide® CSF Tumor Cell Enumeration (TCE) test detecting and quantifying tumor cells in cerebrospinal fluid for diagnosing and monitoring leptomeningeal metastases. The company also manufactures the proprietary CEE-Sure® CSF Collection Tube preservative used to stabilize CSF specimens during transport, and is developing molecular characterization tests (ICC, FISH, NGS) on the same CSF sample.
Is CNSide Diagnostics a public or private company?
CNSide Diagnostics is a private company. It is classified as corporate owned and is currently operating.
When was CNSide Diagnostics founded?
CNSide Diagnostics was founded in 2024. It employs 11 to 50 people.
Where is CNSide Diagnostics based?
CNSide Diagnostics is headquartered in Houston, United States, in the North America region.
How does CNSide Diagnostics make money?
Two revenue lines are on record. Laboratory Testing Services are the primary driver. The others are commercial Payer Agreements.
Who are CNSide Diagnostics's main competitors?
Direct peers on record are Guardant Health, Personalis, Biocept, Natera, Tempus AI, Foundation Medicine, Caris Life Sciences and NeoGenomics. Exact Sciences is listed as a broad incumbent. Burning Rock Biotech is listed as an emerging player.
Does CNSide Diagnostics have an API?
No public API is recorded for CNSide Diagnostics.
What industry is CNSide Diagnostics in?
CNSide Diagnostics's product category is Molecular Diagnostics. Its primary akta.pro industry code is HLAAALAE, Oncology Diagnostics (tumor profiling, MRD, liquid biopsy), with a secondary code of HLAAALAI, Cytology & Histopathology Diagnostics (IHC, ISH, tissue-based assays). Its NAICS code is 621511 and its SIC code is 8071.