Are these panels validated for clinical diagnostic use?

No. All growth factor panels are manufacturer-validated for research use only (RUO). They are suitable for preclinical research, cohort studies, biomarker discovery, and therapeutic development. They are not validated for clinical diagnostic procedures or patient management.

Can other TGF-β superfamily members (activins, BMPs, GDFs) be added?

The standard TGF-β 3-Plex covers TGF-β1/β2/β3. Other superfamily members — activin A, BMP-2, BMP-7, GDF-8 (myostatin), GDF-15 — are not included in the pre-configured panel but may be available via U-PLEX custom configuration or R-PLEX custom development depending on antibody availability. Contact us with your specific growth factor targets for catalog and feasibility assessment.

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MSD V-PLEX · U-PLEX

TGF-β Superfamily · Neurotrophins · Fibrosis

MSD Growth Factor & TGF-β Family Multiplex Assay Services

Q: Why does TGF-β require acid activation before measurement?

TGF-β is secreted as a latent complex — non-covalently bound to latency-associated peptide (LAP), which prevents receptor binding. To measure total TGF-β (the total pool available for biological activity), samples are acidified to pH ~2.5–3.0 for 15–30 minutes to dissociate the latent complex, then neutralized before the assay. This is the standard method for total TGF-β measurement across all platforms (ELISA, MSD, Luminex). Results represent the total TGF-β pool, not the concentration of active TGF-β at the time of sampling. For studies requiring active TGF-β measurement (without acid activation), contact us to discuss protocol options.

Quantify all three TGF-β isoforms (TGF-β1, TGF-β2, TGF-β3) and neurotrophic growth factors (BDNF, β-NGF, FGF-21) using electrochemiluminescence (ECL) — the only multiplex platform offering simultaneous TGF-β isoform quantification from a single 25 µL sample with documented LODs in the low pg/mL range, across human, mouse, and NHP.

Three TGF-β isoforms — three distinct biological functions, one multiplex panel:

TGF-β1 drives fibrosis across organs (IPF, NASH cirrhosis, SSc, CKD) through myofibroblast differentiation and ECM deposition — the dominant pro-fibrotic isoform targeted by fresolimumab and galunisertib. TGF-β2 maintains ocular immune privilege and regulates cardiac valve development and neuronal survival. TGF-β3 promotes scarless fetal wound healing — being investigated as an anti-scarring therapeutic. Unlike inflammatory cytokines, TGF-β is secreted as a latent complex requiring acid activation for measurement. The MSD U-PLEX TGF-β 3-Plex (Biomarker Group 2) measures all three isoforms simultaneously with documented LODs (β1: 9.1, β2: 2.5, β3: 1.4 pg/mL) — distinguishing the fibrosis-regeneration balance that single-plex TGF-β1 ELISAs cannot capture. Neurotrophic factor panels (BDNF, β-NGF, FGF-21) extend coverage to neuronal survival, chronic pain, and metabolic regulation on the same ECL platform.

Inquire About Growth Factor Panels View Panel Configurations

Why Isoform-Specific TGF-β Measurement Matters

TGF-β represents a unique measurement challenge in biomarker research. Unlike classical cytokines that are actively secreted upon stimulation, TGF-β is constitutively produced as a latent complex — non-covalently bound to latency-associated peptide (LAP) — that must be released by acidification, proteolytic cleavage, or integrin-mediated activation to become biologically active. Most immunoassays detect only the active fraction or only after acid activation (total TGF-β). The TGF-β 3-Plex measures total TGF-β1, TGF-β2, and TGF-β3 after standardized acid activation — providing the total pool of each isoform available for biological activity. The distinction between isoforms is critical: TGF-β1 is the dominant pro-fibrotic isoform targeted by fresolimumab and multiple investigational anti-fibrotic therapies; TGF-β2 is the dominant isoform in aqueous humor and vitreous, regulating ocular immune privilege; TGF-β3 promotes scarless wound healing in fetal tissue and is being investigated as an anti-scarring therapeutic (avotermin). Measuring only TGF-β1 — as most single-plex ELISAs do — misses the isoform-specific biology that determines whether the TGF-β response drives fibrosis, immune tolerance, or regenerative repair.

 TGF-β Isoforms — Biological Functions & Research Relevance
TGF-β1 — Master Pro-Fibrotic Cytokine: drives epithelial-mesenchymal transition (EMT), myofibroblast differentiation, and extracellular matrix deposition. Elevated across fibrotic diseases: IPF (lung), NASH/cirrhosis (liver), CKD (kidney), SSc (skin), cardiac fibrosis. Target of fresolimumab (anti-TGF-β) and galunisertib (TGF-βRI kinase inhibitor). LOD in U-PLEX format: ~9.1 pg/mL.
TGF-β2 — Ocular & Neuronal Isoform: the dominant TGF-β in aqueous humor and vitreous, maintaining anterior chamber immune privilege. Critical in cardiac valve development and neuronal survival. Elevated in proliferative vitreoretinopathy and glaucoma. LOD: ~2.5 pg/mL.
TGF-β3 — Regenerative Isoform: promotes scarless fetal wound healing through reduced collagen deposition and altered hyaluronan matrix organization. Investigated as avotermin (recombinant TGF-β3) for scar reduction in research studys. Essential for palatogenesis — TGF-β3 knockout mice have cleft palate. LOD: ~1.4 pg/mL.
BDNF (Brain-Derived Neurotrophic Factor): neurotrophin supporting neuronal survival, synaptic plasticity (LTP), and hypothalamic energy homeostasis. Decreased in major depression; increased by exercise and SSRI treatment. Serum BDNF is a research biomarker in psychiatry and metabolic disease.
β-NGF (beta-Nerve Growth Factor): the prototypical neurotrophin supporting sensory and sympathetic neuron survival. Target of tanezumab (anti-NGF monoclonal antibody) for osteoarthritis and chronic low back pain. Elevated in chronic pain conditions.
FGF-21 (Fibroblast Growth Factor 21): hepatokine-adipokine with insulin-sensitizing and weight-loss effects. Paradoxically elevated in NAFLD/NASH — reflecting FGF-21 resistance. FGF-21 analogs (efruxifermin, pegozafermin) in Phase 3 trials for NASH.

Growth Factor & TGF-β Panel Configurations

Panel	Plex	Analytes	Species	Key Application
TGF-β 3-Plex	3	TGF-β1, TGF-β2, TGF-β3	Human Mouse NHP	Fibrosis, wound healing, immune regulation
Mouse Metabolic Hormone 5-Plex	5	BDNF, FGF-21, Ghrelin (total), Glucagon, Leptin	Mouse	Metabolic disease; energy homeostasis
Human Metabolic 10-Plex Panel 2	10	BDNF, β-NGF, IL-1β, IL-6, IL-8, IL-10, Insulin, Leptin, MCP-1, TNF-α	Human	Neurotrophin + inflammatory + metabolic integration

TGF-β measurement requires acid activation to release the latent complex (pH ~2.5–3.0, 15–30 min, then neutralized). Standardized protocol provided with kit or full-service analysis. The TGF-β 3-Plex is from MSD's U-PLEX Biomarker Group 2 with documented LODs: TGF-β1 ~9.1 pg/mL, TGF-β2 ~2.5 pg/mL, TGF-β3 ~1.4 pg/mL. Additional TGF-β superfamily members (activin A, BMP-2, BMP-7, GDF-8/myostatin, GDF-15) available via U-PLEX or R-PLEX custom development. All services are for research use only.

TGF-β Isoform Biology — From Fibrosis to Regeneration

Fibrosis Research

TGF-β1 drives IPF (lung), NASH/cirrhosis (liver), CKD (kidney), SSc (skin), and cardiac fibrosis through SMAD2/3-dependent EMT and myofibroblast differentiation. The 3-Plex distinguishes TGF-β1-driven fibrosis from TGF-β3-mediated repair. Anti-fibrotic therapies targeting isoform-specific TGF-β signaling include fresolimumab (pan-TGF-β) and galunisertib (TGF-βRI kinase).

Immuno-Oncology

TGF-β mediates immune exclusion in the tumor microenvironment — suppressing CD8+ T-cell infiltration, promoting Treg differentiation, and activating cancer-associated fibroblasts. TGF-β blockade combined with checkpoint inhibitors (anti-PD-L1 + anti-TGF-β bifunctional fusion proteins) is under investigation to overcome stromal barriers to immunotherapy.

Neuroscience & Psychiatry

BDNF is decreased in major depression and increases with antidepressant treatment and exercise. β-NGF is implicated in chronic pain — elevated in fibromyalgia; the target of tanezumab for osteoarthritis pain. TGF-β2 is the dominant CNS isoform regulating neuronal survival and microglial function.

Metabolic Disease

FGF-21 is an insulin-sensitizing hepatokine — paradoxically elevated in NAFLD/NASH, reflecting FGF-21 resistance. FGF-21 analogs (efruxifermin, pegozafermin) are in Phase 3 trials for NASH. BDNF signaling in the hypothalamus suppresses appetite via MC4R neurons.

Ophthalmology

TGF-β2 is the dominant isoform in aqueous humor and vitreous, maintaining anterior chamber immune privilege. Elevated TGF-β2 is implicated in proliferative vitreoretinopathy, glaucoma (trabecular meshwork fibrosis), and corneal scarring.

Wound Healing & Scarring

TGF-β3 promotes scarless fetal wound healing through reduced collagen deposition and altered hyaluronan matrix. The TGF-β1/β3 ratio may determine whether healing proceeds with fibrosis or regeneration — measurable in a single 3-Plex assay. Recombinant TGF-β3 (avotermin) investigated for scar reduction.

Electrochemiluminescence for TGF-β & Growth Factor Detection

Advantages for TGF-β Measurement

Isoform-specific quantification in one well: TGF-β1, TGF-β2, and TGF-β3 share ~70% sequence identity. MSD's spatially separated electrode spots eliminate cross-reactivity between isoforms — each produces an independent signal without the antibody cross-reactivity that confounds multiplex TGF-β measurement on bead-based platforms.
Standardized acid-activation protocol: all three isoforms measured after the same activation step (pH ~2.5–3.0, 15–30 min, neutralized) — eliminating the protocol variability of running three separate TGF-β ELISAs.
Documented per-isoform LODs: TGF-β1 ~9.1 pg/mL, TGF-β2 ~2.5 pg/mL, TGF-β3 ~1.4 pg/mL in the U-PLEX format — per-isoform sensitivity data not available from most TGF-β ELISA kits that report only TGF-β1 sensitivity.
25 µL sample volume: after acid activation and neutralization, only 25 µL is required — preserving precious samples for additional analyses.

TGF-β 3-Plex Assay Specifications

TechnologyMSD U-PLEX

AnalytesTGF-β1, TGF-β2, TGF-β3

LOD (TGF-β1)~9.1 pg/mL

LOD (TGF-β2)~2.5 pg/mL

LOD (TGF-β3)~1.4 pg/mL

Dynamic RangeUp to ~39,000 pg/mL

Sample Volume25 µL (after acid activation)

Activation ProtocolpH ~2.5–3.0, 15–30 min, neutralized

Recommended MatrixSerum, EDTA Plasma

Plate Format96-well MULTI-ARRAY

Read Time~70 seconds per plate

SpeciesHuman, Mouse, NHP

Sample Preparation Notes

Acid activation is mandatory — our lab performs standardized protocol.
Serum TGF-β1 is 2–5× higher than plasma due to platelet release.
BDNF/β-NGF: no activation needed. BDNF diurnal variation noted.

Growth Factor Panel Service Details

Service Package

Item	Full Service	Notes
TGF-β Acid Activation	Included	Standardized pH 2.5–3.0 protocol, documented
Standard Curves	8-point, per isoform	Isoform-specific recombinant calibrators
QC Samples	Multi-level, duplicate	Low, medium, high
Data Report	Per-isoform + ratios	TGF-β1/β2/β3 ratios included
Raw ECL Data	Included	Per-well, per-spot signal values

For Research Use Only. Not for diagnostic procedures.

How to Get Started

Select Panel

Choose TGF-β 3-Plex (fibrosis), neurotrophin panels (BDNF/β-NGF), or combined growth factor profiling.

Collect & Ship

EDTA plasma or serum. TGF-β requires acid activation — we perform this with standardized protocols. Ship on dry ice.

Receive Isoform Data

Receive TGF-β1/β2/β3 concentrations with isoform ratios, neurotrophin data, and QC documentation.

TGF-β Detection: MSD vs Western Blot vs ELISA

Feature	MSD (U-PLEX TGF-β 3-Plex)	Western Blot	Individual ELISA (×3)
Isoform Discrimination	3 isoforms in one well — independent signals	Separate blots or stripping/reprobing	3 separate wells with potential cross-reactivity
Quantitation	Absolute (pg/mL) — 8-point per isoform	Semi-quantitative (band densitometry)	Absolute (pg/mL) — 3 separate curves
Sample Volume	25 µL (after activation)	10–30 µg protein per lane per isoform	300 µL (100 µL × 3)
Throughput	96-well / ~70 sec read	Hours — gel, transfer, block, detect	Hours — 3 separate incubations
Acid Activation	One standardized protocol for all 3 isoforms	N/A — SDS denaturation	3 separate activations, protocol variability risk

What You Receive

Isoform-specific quantitative report — TGF-β1, TGF-β2, TGF-β3 concentrations with per-isoform QC metrics, standard curve parameters, and LOD/LLOQ values (Excel + PDF)
TGF-β isoform ratios — TGF-β1/β3 ratio (fibrosis vs. regeneration) and TGF-β1/β2 ratio, from within-well signals
Raw ECL data — per-well, per-spot signal values with plate layout maps and individual standard curve plots
Acid activation documentation — activation pH, incubation time, neutralization confirmation for each batch
Methods summary — formatted for manuscript Methods sections including TGF-β activation protocol details

Why Choose Electrochemiluminescence for TGF-β Measurement

All three isoforms with documented LODs: TGF-β1 ~9.1 pg/mL, TGF-β2 ~2.5 pg/mL, TGF-β3 ~1.4 pg/mL — per-isoform sensitivity from U-PLEX Biomarker Group 2, independent signals for structurally related isoforms
One activation, three results: eliminates protocol variability of running three separate TGF-β ELISAs with different activation conditions
Within-well isoform ratios — analytically superior: TGF-β1/β3 and TGF-β1/β2 calculated from same-well signals, eliminating cross-well CV
Expands to TGF-β superfamily: activin A, BMP-2/7, GDF-8/myostatin, GDF-15 via U-PLEX or R-PLEX as research evolves
Species-matched panels: human, mouse, NHP on the same platform for translational TGF-β research

Growth Factor & TGF-β Panel FAQ

Why does TGF-β require acid activation before measurement?

TGF-β is secreted as a latent complex non-covalently bound to latency-associated peptide (LAP), which prevents receptor binding. To measure total TGF-β, samples are acidified to pH ~2.5–3.0 for 15–30 minutes to dissociate the latent complex, then neutralized. Without acid activation, only the small fraction of spontaneously activated TGF-β is detected. Our laboratory performs acid activation with a standardized, documented protocol. For studies requiring active TGF-β measurement (without acid activation), contact us to discuss protocol options.

What does the TGF-β1/β3 ratio tell us in research?

The TGF-β1/β3 ratio may reflect the balance between fibrotic repair (TGF-β1-driven: myofibroblast differentiation, collagen deposition, scar formation) and regenerative repair (TGF-β3-driven: scarless healing with reduced collagen and altered ECM). A high ratio is observed in hypertrophic scars and keloids. Therapeutic strategies aim to shift this ratio toward regeneration. The 3-Plex measures both isoforms in the same well for analytically superior ratio precision. This is a research parameter only — not validated for clinical decision-making.

Can other TGF-β superfamily members be added?

Yes. Activin A (cancer cachexia, reproductive biology), BMP-2/BMP-7 (bone formation), GDF-8/myostatin (muscle mass regulation), and GDF-15 (mitochondrial stress, cancer cachexia — target of ponsegromab) are available via U-PLEX custom configuration or R-PLEX development. Contact us with your targets for catalog and feasibility assessment.

How do TGF-β levels differ between serum and plasma?

Serum TGF-β1 is typically 2–5× higher than paired plasma because platelets release TGF-β1 during clotting. For studies where platelet-derived TGF-β is a confounder (e.g., assessing tissue-derived TGF-β), EDTA plasma is preferred. For studies where total circulating TGF-β (tissue + platelet) is the parameter of interest, serum is appropriate. The critical requirement is matrix consistency within a study.

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