This analysis is designed to identify and determine the amount and purity of recombinant Human Growth Hormone fragment 176–191 and AOD-9604. It combines LC-MS, CHNS and HPLC to provide information about peptide identity, net peptide content, peptide purity and potential contamination with other peptides or degradation products.
The test can detect and measure either target compound. It is therefore not necessary to know in advance whether the sample contains rHGH fragment 176–191 or AOD-9604.
rHGH Fragment 176–191
rHGH fragment 176–191, also known as somatropin 176–191, is a peptide corresponding to amino acids 176 to 191 of Human Growth Hormone. It consists of 16 amino acids and represents the C-terminal region of the HGH molecule.
Its molecular weight is approximately 1,799 Da. It differs from AOD-9604 in the first amino acid of its sequence.
AOD-9604
AOD-9604 is a synthetically modified peptide derived from Human Growth Hormone fragment 176–191. Like the rHGH fragment, it contains 16 amino acids, but its sequence begins with tyrosine instead of phenylalanine.
This structural difference allows the two peptides to be distinguished by LC-MS. The molecular weight of AOD-9604 is approximately 1,815 Da.
Analytical Methods
LC-MS – Identification and Contamination Screening
LC-MS is used to confirm the identity of the peptide in the sample. It also provides screening for detectable contamination with other peptides and peptide degradation products.
CHNS – Net Peptide Content Determination
CHNS elemental analysis measures the carbon, hydrogen, nitrogen and sulphur content of the sample. The measured values can be used to determine Net Peptide Content.
Because the sample is combusted during CHNS analysis, the result is not affected by solubility issues that may complicate chromatographic measurement of peptide amount.
HPLC – Peptide Purity Determination
HPLC is used to determine peptide purity and the relative proportion of the main peptide component compared with chromatographically detectable impurities.
What the Analysis Determines
- Identity of rHGH fragment 176–191 or AOD-9604
- Amount of peptide in the sample
- Net peptide content determined by CHNS
- Peptide purity determined by HPLC
- Presence of other peptides or degradation products detected by LC-MS
- Differentiation between rHGH fragment 176–191 and AOD-9604
Analysis Parameters
- Target compounds: rHGH fragment – somatropin 176–191 and AOD-9604
- CAS number of AOD-9604: 221231-10-3
- Molecular weight of AOD-9604: 1,815 Da
- AOD-9604 sequence: H-Tyr-Leu-Arg-Ile-Val-Gln-Cys(1)-Arg-Ser-Val-Glu-Gly-Ser-Cys(1)-Gly-Phe-OH
- CAS number of rHGH fragment: 66004-57-7
- Molecular weight of rHGH fragment: 1,799 Da
- rHGH fragment sequence: H-Phe-Leu-Arg-Ile-Val-Gln-Cys(1)-Arg-Ser-Val-Glu-Gly-Ser-Cys(1)-Gly-Phe-OH
- Identification method: LC-MS
- Amount determination method: CHNS
- Peptide purity method: HPLC
- Detection limit: less than one twentieth of the usual dosage per vial
- Result format for lyophilizates: mg per vial and peptide purity
- Alternative result format: m/m purity and peptide purity
- Minimum lyophilizate sample: one whole unopened vial containing the lyophilizate
- Minimum raw API powder sample: 30 mg in a sealed glass vial to prevent moisture absorption
- Average turnaround time: 7 business days
Important Notice
The alternative m/m purity result format is intended exclusively for raw API powders. For lyophilized samples, the standard result format provides the peptide amount in mg per vial together with peptide purity.
Additional Analyses
TFA Analysis
- Detection and measurement of trifluoroacetic acid (TFA) in the sample. Results are reported in mg per vial.
Raw Data
- Delivery of the available raw analytical data from the primary test and all applicable additional analyses.
Fentanyl Presence Analysis
Alternative Result Format – m/m Purity
- Alternative reporting of the result as mass-by-mass purity. This option is intended exclusively for raw API powders.
Variance Testing
- Analysis of multiple sample units to assess variation within a single batch. All submitted samples must originate from the same batch of the same product.
pH Measurement
Endotoxin Analysis
- Measurement of bacterial endotoxins, particularly lipopolysaccharides (LPS), in the sample. This analysis is available only for finished products and should not be ordered for raw powders.
- The standard test provides accurate results up to 10 EU per vial. Values above 10 EU per vial are estimated and require an additional test with a different dilution for precise determination. Sending two vials is therefore recommended.
- Where endotoxin levels above 10 EU per vial are expected, the method can be calibrated for the higher range in advance.
Additional Report
- A separate additional laboratory report issued under a different client name.
Sterility Testing
- TAMC and TYMC testing checks the product for the presence of bacteria, yeasts and moulds. Additional unopened sample units must be submitted for analysis. The average turnaround time for this test is 14 days.
Heavy Metals Analysis
- Detection of arsenic, cadmium, lead and mercury in the sample. Testing for other metals can be arranged individually.
