CJC-1295 reconstitution is the laboratory step that converts a lyophilized (freeze-dried) research peptide into a stable, workable solution for in-vitro and preclinical experiments. Because CJC-1295 is a synthetic 29–30 amino-acid GHRH (growth-hormone-releasing hormone) analog with a modified backbone, its handling differs in meaningful ways from simpler peptides: the DAC (Drug Affinity Complex) variant carries a maleimidopropionic acid group intended for covalent albumin binding, and the non-DAC variant (often labeled CJC-1295 without DAC, functionally comparable to mod GRF 1-29) behaves differently in solution. This guide gives a compound-specific reconstitution and concentration protocol for CJC-1295 research preparations so that bench work is reproducible and concentration is known.
Research Use Only. CJC-1295 and all related compounds discussed here are supplied strictly for laboratory research use only. They are not for human or veterinary use, are not a drug or dietary supplement, have not been evaluated by the FDA, and are not intended to diagnose, treat, cure, or prevent any disease. All handling described below is laboratory bench procedure for preparing research reagents.
What Makes CJC-1295 Different to Reconstitute
CJC-1295 is delivered as a white lyophilized powder, typically in a 2 mg or 5 mg vial under vacuum. The peptide itself is a solid deposited on the vial wall or base. Two structural features drive its handling requirements in the lab:
- Backbone substitutions. CJC-1295 incorporates amino-acid substitutions (D-Ala, Gln, Ala, Leu) at positions that resist enzymatic cleavage by DPP-IV. This confers relatively good aqueous stability compared with native GHRH, but the peptide remains sensitive to heat, agitation, and repeated freeze-thaw.
- The DAC group (DAC variant only). The DAC form bears a reactive linker designed to conjugate to serum albumin in research models. In vitro it does not change reconstitution mechanics dramatically, but it does mean the compound is used in longer-half-life study designs. See the CJC-1295 with DAC research guide for the receptor pharmacology and study-model context.
For the underlying chemistry of the diluent, review bacteriostatic water for peptide research, and for the general workflow that applies to any lyophilized peptide, see the peptide reconstitution guide.
Choosing the Reconstitution Solvent
For CJC-1295 research preparations, bacteriostatic water (0.9% benzyl alcohol in sterile water) is the standard diluent. The benzyl alcohol acts as a bacteriostatic preservative, which matters because CJC-1295 solutions are frequently aliquoted and stored over multiple study sessions rather than used in a single run. Sterile water or 0.9% sodium chloride can be used when a single-use, same-day preparation is planned and no preservative is required.
| Diluent | Best for | Notes |
|---|---|---|
| Bacteriostatic water | Multi-session stock that is aliquoted/refrigerated | Benzyl alcohol limits microbial growth; preferred default |
| Sterile water for injection | Single-use, same-day in-vitro assays | No preservative; discard remainder |
| 0.9% NaCl | Assays requiring isotonic conditions | Slightly less common; check assay compatibility |
Step-by-Step Reconstitution Protocol
- Equilibrate. Bring the sealed vial and diluent to room temperature to prevent condensation forming on cold glass, which can invite contamination.
- Sanitize. Wipe both rubber stoppers with a 70% isopropyl alcohol swab and allow them to dry.
- Draw the diluent. Using a sterile syringe, withdraw the calculated volume of bacteriostatic water (see the concentration section below).
- Add slowly down the wall. Insert the needle at an angle and let the diluent run down the interior glass wall — do not squirt it directly onto the peptide cake. Shear force from a direct jet can fragment or denature the peptide.
- Dissolve gently. Let the vial stand for 1–2 minutes, then swirl slowly or roll it between your palms. Never shake or vortex. Agitation introduces air-water interface stress that promotes aggregation and can cloud the solution.
- Inspect. A correctly reconstituted CJC-1295 preparation is clear and colorless with no visible particulates. Discard any solution that remains cloudy after gentle dissolution.
- Label. Record compound, variant (DAC vs non-DAC), concentration, diluent, and date directly on the vial.
Concentration Math for CJC-1295
Concentration is simply total peptide mass divided by total diluent volume. Because CJC-1295 research is often planned in microgram quantities, expressing the result in micrograms per 0.01 mL (a common working reference volume) makes bench calculations fast.
Formula: concentration (mcg per 0.01 mL) = [peptide mass in mcg] ÷ [diluent mL ÷ 0.01]
| Vial | Bacteriostatic water added | Resulting concentration | Per 0.01 mL |
|---|---|---|---|
| 5 mg (5000 mcg) | 1.0 mL | 5 mg/mL | 50 mcg |
| 5 mg (5000 mcg) | 2.0 mL | 2.5 mg/mL | 25 mcg |
| 5 mg (5000 mcg) | 2.5 mL | 2 mg/mL | 20 mcg |
| 2 mg (2000 mcg) | 2.0 mL | 1 mg/mL | 10 mcg |
Adding a larger diluent volume yields a more dilute solution and finer measurement resolution per unit volume — useful when a study design calls for small, precise quantities. A smaller volume concentrates the preparation. For a walkthrough of the arithmetic across any vial size, use the peptide research concentration calculator guide. The CJC-1295 with DAC 5mg vial maps directly onto the 5 mg rows above.
Storage and Stability After Reconstitution
Once in solution, CJC-1295 is far less stable than the lyophilized powder, so storage discipline preserves experimental validity.
- Lyophilized (unopened): store at −20°C; long-term stability is best in the frozen solid state, protected from light.
- Reconstituted stock: refrigerate at 2–8°C. Research handling references generally treat bacteriostatic-water solutions as usable for a period of weeks under refrigeration, whereas preservative-free preparations should be treated as short-lived.
- Minimize freeze-thaw. Repeated freezing and thawing of solution drives aggregation. If long storage of solution is required, aliquot into single-use portions before freezing so each is thawed only once.
- Protect from light and heat. Keep vials out of direct light and away from heat sources at all times.
For the temperature and degradation science behind these rules, see peptide storage and stability in the lab, and for the broader bench framework, the parent Peptide Handling & Lab Practices guide.
DAC vs Non-DAC: Handling Notes
The reconstitution mechanics are essentially identical for both variants — same solvent, same gentle technique, same concentration math. The practical difference is study design rather than bench prep: the DAC variant is engineered for extended albumin binding in research models and is therefore typically prepared as a longer-lived stock, while non-DAC CJC-1295 is studied on shorter timescales. Always label the variant explicitly, because mixing the two in a dataset without clear identification undermines reproducibility.
Common Lab Errors to Avoid
- Shaking the vial — causes foaming and peptide aggregation; swirl only.
- Direct-jetting diluent onto the powder — shear stress denatures peptide; run it down the wall.
- Unlabeled concentration — every calculation downstream depends on it; label immediately.
- Room-temperature storage of solution — accelerates degradation; refrigerate promptly.
- Using cloudy solution — indicates aggregation or contamination; discard.