Peptide reference · 29-residue GHRH analog
CJC-1295 (no DAC) COA check: molecular weight, formula and what to look for
Use these reference values to check the identity result on a CJC-1295 (no DAC) Certificate of Analysis. The theoretical average molecular weight of CJC-1295 (no DAC) is 3,367.90 Da and the monoisotopic mass is 3,365.894 Da.
Check a CJC-1295 (no DAC) COA nowCJC-1295 (no DAC) reference data
| Name | CJC-1295 (no DAC) |
|---|---|
| Also known as | Mod GRF (1-29), Modified GRF 1-29, Tetrasubstituted GRF(1-29) |
| Type | 29-residue GHRH analog |
| Molecular formula | C152H252N44O42 |
| Average molecular weight | 3,367.90 g/mol (Da) |
| Monoisotopic mass | 3,365.8936 Da |
| Residues | 29 |
| Sequence | Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH₂ |
| Reference source | PubChem CID 91976842 (formula and mass cross-checked) |
Expected mass spectrometry ions
A CJC-1295 (no DAC) COA may list one of these m/z values instead of the neutral mass. That is still consistent with CJC-1295 (no DAC). How charge states work.
| Ion | m/z (monoisotopic) | m/z (average) |
|---|---|---|
| [M+3H]3+ | 1,122.97 | 1,123.64 |
| [M+4H]4+ | 842.48 | 842.98 |
| [M+5H]5+ | 674.19 | 674.59 |
| [M+6H]6+ | 561.99 | 562.32 |
What else can show up on a CJC-1295 (no DAC) COA
Masses calculated from CJC-1295 (no DAC)'s formula and sequence for the adducts, degradation products and synthesis impurities a lab report can show. A match tells you what the extra peak probably is.
| Signal | Value | What it means |
|---|---|---|
| Na adduct, deconvoluted (M + 21.98) | 3,387.88 Da | Sodium adduct: an MS artifact, not a separate impurity. The [M+Na]+ ion itself is at M + 22.99 |
| K adduct, deconvoluted (M + 37.96) | 3,403.85 Da | Potassium adduct: an MS artifact. The [M+K]+ ion itself is at M + 38.96 |
| TFA adduct (M + 113.99) | 3,479.89 Da | Trifluoroacetic acid from purification seen as an adduct; residual TFA salt is real vial content |
| M + 0.98 (deamidation) | 3,366.88 Da | Asn/Gln deamidation; overlaps the natural isotope peak, needs high-resolution MS |
| M + 0.98 (free acid) | 3,366.88 Da | C-terminal amide hydrolysed or free-acid synthesis error |
| M − 18 (aspartimide) | 3,347.88 Da | Aspartimide formation at Asp |
Deletion sequences (11): one residue missing
| Signal | Value | What it means |
|---|---|---|
| des-Tyr (M − 163.06) | 3,202.83 Da | Deletion sequence missing one Tyr |
| des-Ala (M − 71.04) | 3,294.86 Da | Deletion sequence missing one Ala |
| des-Asp (M − 115.03) | 3,250.87 Da | Deletion sequence missing one Asp |
| des-Leu/Ile (M − 113.08) | 3,252.81 Da | Deletion sequence missing one Leu/Ile |
| des-Phe (M − 147.07) | 3,218.83 Da | Deletion sequence missing one Phe |
| des-Thr (M − 101.05) | 3,264.85 Da | Deletion sequence missing one Thr |
| des-Gln (M − 128.06) | 3,237.83 Da | Deletion sequence missing one Gln |
| des-Ser (M − 87.03) | 3,278.86 Da | Deletion sequence missing one Ser |
| des-Arg (M − 156.10) | 3,209.79 Da | Deletion sequence missing one Arg |
| des-Lys (M − 128.09) | 3,237.80 Da | Deletion sequence missing one Lys |
| des-Val (M − 99.07) | 3,266.83 Da | Deletion sequence missing one Val |
Adduct rows are deconvoluted masses (the shift seen against [M+H]+); the singly charged [M+Na]+ ion itself sits at M + 22.99. Deletion masses alone can't say which copy of a repeated residue is missing.
At over 3 kDa, CJC-1295 (no DAC) is harder to purify; 98% or higher with one sharp main peak is a strong result. The full checklist is in how to read a peptide COA.
CJC-1295 (no DAC)-specific things to watch
"CJC-1295 without DAC" and "Mod GRF (1-29)" are the same molecule: a 29-residue GHRH analog with four substitutions and a C-terminal amide, about 3367.9 Da.
The most common COA mix-up is between the no-DAC and with-DAC versions, which differ by roughly 279 Da. A no-DAC vial should show a mass near 3368 Da; a result near 3647 Da means you have the DAC version.
At this size, ESI spectra show multiple charge states (for example around 1123.6 m/z for 3+ and 842.9 m/z for 4+). A good COA reports the deconvoluted mass and includes the spectrum image.
Compounds with similar mass
If a COA's mass is off, compare it with these neighbors. A match to one of them can point to a mislabeled product.
- Sermorelin: 3,357.88 Da (-10.02 Da)
- Thymosin Alpha-1: 3,108.28 Da (-259.62 Da)
- CJC-1295 (with DAC): 3,647.19 Da (+279.29 Da)
Sources
- PubChem CID 91976842: CJC-1295 (no DAC) formula and reference mass.
- CIAAW: Standard atomic weights: Used to calculate average molecular weights.
- NIST CODATA: proton mass: Used to convert m/z charge states to neutral mass.
- PeptideCOACheck methodology: How the checker's thresholds work.
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Frequently asked questions
What is the molecular weight of CJC-1295 (no DAC)?
The average molecular weight of CJC-1295 (no DAC) (C152H252N44O42) is 3,367.90 Da and its monoisotopic mass is 3,365.8936 Da, calculated from the molecular formula and cross-checked against PubChem CID 91976842.
What other masses can show up on a CJC-1295 (no DAC) COA?
Besides the main peak, a CJC-1295 (no DAC) COA can show a sodium adduct (deconvoluted mass near 3,387.88 Da) and aspartimide near 3,347.88 Da. The table on this page lists every expected variant with its mass.
For laboratory research use only. This page describes analytical chemistry data. It is not medical advice and makes no claim about effects in humans or animals.