Follistatin-344 (FS-344) — 1 mg from Peptide Tech is a recombinant, lyophilized research-use-only (RUO) glycoprotein supplied with batch-level traceability and third-party testing. Derived from the human FST gene product (344-aa precursor), this material is engineered for in-vitro studies of TGF-β superfamily biology (e.g., activin/myostatin systems), binding/neutralization assays, and protein analytics where sequence fidelity, documentation, and cold-chain integrity are critical.

Specifications

Property	Details
Protein Name	Follistatin (FS-344 precursor; human)
Gene / UniProt	FST / P19883
Length / Construct	344 aa precursor; supplied construct and any tags are lot-specific (commonly aa 30–344). See COA/label.
Molecular Weight	~38 kDa polypeptide (unglycosylated); apparent 36–44 kDa with glycosylation (lot-dependent; see COA).
Glycosylation	Yes (glycoprotein). Expression system and glycoform reported on the COA.
Appearance	White to off-white lyophilized protein
Content per Vial	1 mg
Container	3 mL Type I glass vial with butyl stopper & flip-off seal
Purity / Identity	≥ 98% by SDS-PAGE/RP-HPLC; identity by MS/Western (batch COA via on-vial QR)
Buffer / Excipients	Lot-specific lyoprotectants (see COA)
Solubility	Reconstitute in sterile water or PBS; for working stocks use carrier (e.g., 0.1% BSA) per SOP to minimize adsorption.
Intended Use	Laboratory research only (RUO). Not for human or animal use.

Molecular Structure

Follistatin is a multi-domain glycoprotein comprising three follistatin-like domains (FSD1–FSD3) and a C-terminal region; small-molecule 2D depictions are not applicable. Explore domain architecture and models here:

UniProt feature viewer (FST / P19883): link
SWISS-MODEL / AlphaFold entry for P19883: link

Key Features of Peptide Tech

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Third-Party U.S. Lab Testing — purity, quantity, endotoxin
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Potential Applications in Research (RUO)

Strictly for in-vitro, cell-based, or biochemical experiments. No health, diagnostic, or therapeutic claims.

Ligand binding & neutralization assays with activins/myostatin/BMPs using SPR/BLI or ELISA readouts.
SMAD reporter workflows (e.g., SMAD2/3 luciferase) to quantify pathway modulation under defined ligand challenge.
Co-culture and differentiation models (myogenic or stromal cell lines) to map phenotype-linked transcriptional changes in vitro.
Protein analytics — SDS-PAGE/WB, SEC-MALS, and LC–MS stability/recovery studies across buffers and temperatures.
Comparative bioassays versus FST isoforms (FS-315/FS-288) to profile domain contributions and potency rank-order.

Quality, Storage & Handling

Each lot includes a QR-linked COA and independent U.S. lab verification of purity, quantity, and endotoxin. Use aseptic technique throughout.

Storage (lyophilized): −20 °C long-term or 2–8 °C short-term; protect from light and moisture.
After reconstitution: Aliquot and store at ≤ −20 °C (or −80 °C per SOP); avoid repeated freeze–thaw.
Buffers & carriers: For working solutions, include inert protein carrier (e.g., 0.1% BSA) to minimize surface loss; verify compatibility with your assay.

Shipping & Fulfillment

Ships in validated cold-chain packaging. In-stock orders placed before the daily cutoff ship the same day. 2-Day FedEx/UPS is standard, with overnight options available. Automated text/email updates included; international shipping available where permitted.

Compliance & RUO Disclaimer

For laboratory research only. Not a drug, cosmetic, food, or household chemical. Not for human or animal use, ingestion, diagnostic, or therapeutic applications. Buyers warrant they are qualified to handle RUO materials under applicable laws and institutional guidelines. COAs available via QR or upon request.

FAQs

Is this the 344-aa protein or the 30–344 mature region?: Our FS-344 is produced from the human FST sequence; the supplied region and any fusion tags are listed on the lot COA (commonly aa 30–344 for mature domain coverage).
What purity do you provide?: Each 1 mg vial is ≥ 98% by SDS-PAGE/RP-HPLC with MS/Western identity confirmation; third-party testing is performed on every lot (COA via on-vial QR).
How should I reconstitute and store it?: Use sterile water or PBS. For working stocks, include 0.1% BSA or another approved carrier, aliquot, and store frozen to avoid repeat freeze–thaw.
Which in-vitro assays are typical?: Common RUO applications include activin/myostatin neutralization assays, SMAD reporter readouts, protein binding kinetics by SPR/BLI, and SDS-PAGE/LC–MS stability panels.