Recombinant human hepatocyte growth factor (rhHGF), two-chain α/β heterodimer, c-Met (MET) receptor ligand: preparation and storage
Intended for research use only. Not a medicinal product.
Contents (8 sections)
Distinguish pro-HGF from the active form
R&D Systems describes HGF as an inactive single-chain precursor that becomes an active disulfide-linked heterodimer after proteolytic processing. Total protein quantity without its activation form is therefore an incomplete reagent description. Establish what the analytical standard actually measures. [1]
For 294-HG, the manufacturer specifies Sf21 expression, construct boundaries and sequence variants. This describes that product, not every HGF reagent. Check your LOT, expression system and active form; a shared name does not eliminate construct differences.
Carrier protein changes the reconstitution instructions
R&D separates 294-HG containing BSA from carrier-free 294-HG/CF. The former specifies PBS containing at least 0.1% albumin; the latter specifies PBS without that mandatory addition. Both examples use 100 µg/mL. These are product-specific instructions, not an automatic Longeva preparation recipe. [1]
Check whether albumin is present in the dry material and permitted by the assay. Adding protein to a carrier-free product changes the matrix. Immunoassays, total-protein measurements and cell assays must account for that change in their controls and calibration.
Checking the final matrix
Before preparing a stock supply, reproduce the complete path to the working sample: reconstitution, intermediate dilution and addition to medium. Record pH, salts, protein additives and time in each vessel. Inspection immediately after reconstitution does not establish HGF condition at the end of the experiment.
Do not apply an acidic or organic-solvent recipe intended for another substance. If extra filtration is required, check membrane compatibility and HGF recovery; nominal starting concentration does not account for filtration losses. The HGF-free control needs matching vehicle and protein additives.
A dilution example avoiding impractically small volumes
For an educational calculation, 100 µg/mL equals 100,000 ng/mL. Reaching 10 ng/mL requires an overall 1:10,000 dilution. Instead of pipetting an impractically small amount, it can be divided mathematically into two 1:100 steps: bring 10 µL to 1 mL, then bring 10 µL of that intermediate to 1 mL again. This is arithmetic, not an HGF concentration recommendation.
Each step needs compatible vehicle. Calculate albumin and other additive changes separately. Molarity requires the defined heterodimeric form, not one chain mass. Biological activity cannot be derived from protein mass alone.
What activity in a certificate means
R&D tests 294-HG activity by inducing IL-11 secretion in Saos-2 cells. This is a defined functional endpoint, not a promise of every effect in all cell systems. Define your own experimental endpoint and use a comparable reference material. [1]
Total protein, molecular identity, chain state and cell activity require different methods. A high-purity COA does not replace the required functional control. Compare the new batch and previous reference within one run using matched cells, timing and vehicle.
Storage depends on form and formulation
For the referenced recombinant HGF, R&D specifies frozen storage as supplied and separate periods after reconstitution. Its refrigerated in-use period explicitly requires sterile conditions. Those periods do not automatically apply to another construct or vehicle. The supplied and reconstituted forms must be distinguished. [1]
A freezer for long dry-vial storage and refrigerator for a short period are appropriate only where the specification allows them. Intended use within a week or month does not establish stability. Solutions need their own protocol; when freezing is allowed, aliquots reduce unnecessary thaws.
Record LOT, vehicle, concentration, reconstitution date and temperature history. Compare fresh and stored HGF in one functional run when evaluating an in-use period. Assess an unknown temperature excursion separately rather than accepting it based on clarity alone.
Frequently asked questions
Is the name HGF enough to choose a protocol?
No. The active form, construct, expression system and product formulation are needed.
Should albumin always be added?
No: carrier and carrier-free products have different instructions, and the assay must tolerate the additive.
Does purity mean identical cell activity?
No. Chemical profile and a functional assay measure different properties and need separate comparisons.
Sources
- R&D Systems: Recombinant Human HGF, 294-HG and 294-HG/CF. Specification, formulations, activity and storage read 26 October 2026; another manufacturer example, not a Longeva COA.
Product and current sizes · Monograph and research · COA
A laboratory guide for research material; no human-use regimen is provided.
End of article
HGF
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