Researcher organizing samples for a receptor assay

Growth Axis · Laboratory protocol

Tesamorelin

Stabilized GHRH(1-44) analog carrying a trans-3-hexenoyl modification that resists DPP-4 cleavage. Same receptor as CJC-1295, different backbone and different stabilization strategy.

For laboratory research use only. Material is supplied as a research reference standard and is not approved by Health Canada. Protocols below are compiled from published literature and supplier documentation; they are reference information, not medical advice. Anyone with a health condition or on medication should speak to a physician first.

Before you begin

• Lot-matched certificate and laboratory notebook
• Calibrated pipettes, low-binding tubes and suitable PPE
• Validated solvent, assay reagents and model-specific SOP
• Appropriate positive, negative and vehicle controls

Workflow

1Review the lot-matched COA and record identity, purity, batch number and received condition.
2Let the sealed vial equilibrate to room temperature before opening to limit condensation.
3Calculate the target stock concentration with C = mass / volume. Use only a solvent validated for the planned assay.
4Add solvent slowly down the vial wall, mix gently and avoid vortexing unless the validated method permits it.
5Prepare a log-spaced pilot concentration series; determine the usable range empirically instead of assuming a biological dose.
6Run the defined controls and technical replicates alongside every plate or experiment.
7Record preparation time, temperature, equipment, deviations and raw-data file locations.

Assay design

GHRH-R reporter or secretion model. Where DPP-4 resistance is the research question, the comparison arm must be an unmodified GHRH analog run in the same matrix.

Required controls

Vehicle-only negative control
Receptor-null or antagonist condition
Validated reference ligand
Untreated viability control

Reported protocol

Standard daily: 1.0 mg to 2.0 mg daily
Timing: Once daily before bedtime, or on waking in a fasted state
Route: Subcutaneous
Cycle length: 8 to 12 weeks continuous

Diluent

Sterile bacteriostatic water (0.9% benzyl alcohol) for multi-withdrawal stock, or sterile water for injection where a preservative-free stock is required by the assay.

Reconstitution concentrations

Solvent volume sets the stock concentration for this 20 mg vial. Lower volume gives a more concentrated stock and smaller working aliquots; higher volume gives a more dilute stock that is easier to measure accurately.

Stock concentration by solvent volume for a 20 mg vial
Solvent added	Stock concentration	Per 0.1 mL	Per unit (U-100)
1 mL	20 mg/mL	2 mg	200 mcg
2 mL	10 mg/mL	1 mg	100 mcg
3 mL	6.67 mg/mL	666.67 mcg	66.67 mcg
5 mL	4 mg/mL	400 mcg	40 mcg

Working range

GHRH-R activation work runs a log-spaced nanomolar series, as for other GHRH analogs.

GHRH-R reporter or secretion model. Where DPP-4 resistance is the research question, the comparison arm must be an unmodified GHRH analog run in the same matrix.

Stability

Lyophilized: Stable sealed and dry at the certificate temperature.
In solution: Establish empirically for your solvent and container.

Handling notes

Equilibrate before opening; this is a larger peptide and the cake takes longer to go into solution.
Allow full dissolution before drawing. Swirl, wait, inspect against a bright background.
For degradation studies, include serum or a DPP-4 source in the comparison arm, not just buffer.

Documentation checklist

Record lot and COA, mass balance, solvent and concentration, preparation timestamp, storage history, plate map, replicate plan, instrument settings, exclusions and deviations. Preserve raw data and analysis code with the experiment record.