AssayIndex
Growth-hormone axis peptides

MGF

mechano growth factor · IGF-1Ec (E-domain) · C121H200N42O37 · monoisotopic 2886.5117 Da. The index holds 32 assay reports on this compound across 7 batches from 7 suppliers.

32 reports7 batchesmedian 98.73 %index spec 97.5 %
Section 1

Analytical fingerprint

Hand-authored chemistry. These properties describe the substance and do not change when a record is added.

The 24-residue E-domain peptide. Routine synthetic assay, moderate purity, thin coverage. Its analytical value in the index is as the deconjugated reference for PEG-MGF: the same lot assayed before and after PEG cleavage should give matching impurity profiles, and where it does not, the conjugation step introduced something.

Molecular formula
C121H200N42O37
Monoisotopic mass
2886.5117Da
Average mass
2888.19Da
Residues
24
Nominal retention (RG-2, 30 min)
11.62min
Retention window
0.30min
Counter-ion as usually shipped
acetate
Typical label claims
2 mg · 5 mg
Analytical difficulty (index scale)
1.10 — straightforward
Purity is a defined quantity
YES
Section 2

Representative chromatogram

Drawn from this page's own medians. Not a scan, not an illustration, and not any single report.

02294458968839178 MGF11.62 min · 98.73 % 11.94 same trace · ×200 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. A representative MGF trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 98.73 % area at the nominal retention time of 11.62 min, and each impurity peak carries the median area the index has observed for that named species at its characteristic retention offset. It is not a scan of any single report — every individual record's own chromatogram is on its own page. The lower panel is the same trace at a stated vertical expansion, baseline-corrected, so the impurities are visible; the main peak runs off-scale there by design. Baseline noise is seeded from the compound slug.
Section 3

What the index has observed

Arithmetic over the 32 records the index holds. Aggregates on this page are computed over the records the index holds, which are not a random sample of the material on the market. Lots that get tested are lots someone chose to test. Read every figure here as a description of this dataset rather than as an estimate of a population.

Median purity 98.73% n=32
Interquartile range 0.64pp n=32
Minimum 97.64% n=32
Maximum 99.77% n=32
Pass rate vs spec 100.0% n=32
Median recovery vs claim 97.9% n=15
Median water 4.63% n=32
Median |mass error| 2.5ppm n=25
036992.093.094.095.096.097.098.099.0100.092.00–92.25 %: n=092.25–92.50 %: n=092.50–92.75 %: n=092.75–93.00 %: n=093.00–93.25 %: n=093.25–93.50 %: n=093.50–93.75 %: n=093.75–94.00 %: n=094.00–94.25 %: n=094.25–94.50 %: n=094.50–94.75 %: n=094.75–95.00 %: n=095.00–95.25 %: n=095.25–95.50 %: n=095.50–95.75 %: n=095.75–96.00 %: n=096.00–96.25 %: n=096.25–96.50 %: n=096.50–96.75 %: n=096.75–97.00 %: n=097.00–97.25 %: n=097.25–97.50 %: n=097.50–97.75 %: n=197.75–98.00 %: n=198.00–98.25 %: n=198.25–98.50 %: n=998.50–98.75 %: n=498.75–99.00 %: n=699.00–99.25 %: n=799.25–99.50 %: n=199.50–99.75 %: n=199.75–100.00 %: n=1median 98.73 Purity (% area) Reports
Figure 2. Purity distribution across all 32 MGF records. Dashed line is this compound's median (98.73 %); the solid vertical is the index acceptance specification for the growth-hormone axis peptides class (97.5 %). Domain is fixed at 92–100 % on every purity histogram on this site so that compounds can be compared by eye — a wide distribution here is a hard compound, a narrow one is an easy one, and neither is a statement about the suppliers.
Section 4

By supplier

Suppliers with fewer than two purity records on this compound are omitted from the figure rather than drawn as a line. The full table, including the thin cells, is on the by-supplier page.

97.597.998.398.799.199.599.9SWBSWB: Q1 98.36, median 98.41, Q3 98.89, n=12n=12BCHBCH: Q1 98.71, median 98.89, Q3 99.04, n=10n=10MKMMKM: Q1 98.25, median 98.30, Q3 98.40, n=3n=3SGNSGN: Q1 99.05, median 99.06, Q3 99.41, n=3n=3TFCTFC: Q1 99.48, median 99.52, Q3 99.56, n=2n=2 Purity (% area)
Figure 3. MGF purity by supplier, ordered by coverage. The vertical line is the index acceptance specification. Boxes that overlap are suppliers this dataset cannot separate, and most of them overlap.

Full per-supplier table with n= caveats →

Section 5

Characteristic impurities and degradants

The left three columns are authored chemistry — what this molecule characteristically carries and where it elutes. The right three are what the index has actually reported.

Named speciesΔRT (min, RG-2)Δ mass (Da)Seen inMedian % areaMax % area
deamidated (+1 Da)-0.24+0.984100%0.261.06
truncated (1-20)-1.22-486.271100%0.231.15
acetyl adduct (+42 Da)+0.40+42.011100%0.240.87
aspartimide (−18 Da)+0.32-18.01197%0.290.61

Degradation pathways

  • Asn deamidation
  • rapid serum proteolysis (not an assay concern, but the reason PEG-MGF exists)

Full impurity profile, with what each named species implies about the synthesis →

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q10n<3—
2024-Q20n<3—
2024-Q30n<3—
2024-Q42n<399.45–99.59
2025-Q11n<3—
2025-Q2399.0699.04–99.77
2025-Q3398.3098.20–98.50
2025-Q41n<3—
2026-Q11298.4197.64–99.03
2026-Q21098.8998.48–99.20
2026-Q30n<3—

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent MGF records of 32.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043516BCHBCH-2511-D7240PeptideMeter2026-Q299.035.80—Supplier-supplied0PASS
AX-2026-043515BCHBCH-2511-D7240Janoshik2026-Q298.774.95—Supplier-supplied0PASS
AX-2026-043514BCHBCH-2511-D7240Nordanalyt2026-Q299.175.8997.9Supplier-supplied1MARGINAL
AX-2026-043517BCHBCH-2511-D7240PeptideMeter2026-Q298.665.59102.1Supplier-supplied1MARGINAL
AX-2026-043520BCHBCH-2511-D7240Janoshik2026-Q298.905.81—Supplier-supplied1MARGINAL
AX-2026-043512BCHBCH-2511-D7240Kestrel2026-Q299.045.56103.4Supplier-supplied1MARGINAL
AX-2026-043511BCHBCH-2511-D7240Janoshik2026-Q298.696.01—Supplier-supplied0PASS
AX-2026-043513BCHBCH-2511-D7240Kestrel2026-Q298.485.7799.6Buyer-sourced0PASS
AX-2026-043519BCHBCH-2511-D7240Medutest2026-Q298.876.14—Laboratory-retained1FAIL
AX-2026-043518BCHBCH-2511-D7240Janoshik2026-Q299.205.2897.9Supplier-supplied1MARGINAL
AX-2026-042449SWBSWB-2601-E6319Janoshik2026-Q198.404.05—Buyer-sourced0PASS
AX-2026-042450SWBSWB-2601-E6319Janoshik2026-Q198.374.34—Supplier-supplied1MARGINAL
AX-2026-042445SWBSWB-2601-E6319VendorInvestigate2026-Q197.644.77—Buyer-sourced1MARGINAL
AX-2026-042448SWBSWB-2601-E6319Janoshik2026-Q198.414.9798.5Supplier-supplied0PASS
AX-2026-042451SWBSWB-2601-E6319Janoshik2026-Q198.874.58—Supplier-supplied0PASS
AX-2026-042446SWBSWB-2601-E6319Janoshik2026-Q198.414.61102.4Supplier-supplied1MARGINAL
AX-2026-042453SWBSWB-2601-E6319Janoshik2026-Q198.324.4091.1Supplier-supplied0PASS
AX-2026-042452SWBSWB-2601-E6319Janoshik2026-Q199.034.64—Supplier-supplied1MARGINAL
AX-2026-042447SWBSWB-2601-E6319Janoshik2026-Q198.965.15106.9Supplier-supplied0PASS
AX-2026-042442SWBSWB-2601-E6319Medutest2026-Q197.985.0395.7Laboratory-retained0PASS
AX-2026-042444SWBSWB-2601-E6319Janoshik2026-Q198.974.4197.0Supplier-supplied0PASS
AX-2026-042443SWBSWB-2601-E6319PeptideMeter2026-Q198.514.85—Supplier-supplied1MARGINAL
AX-2025-020149GGPepsGGPE-2506-T9249Janoshik2025-Q498.343.70—Supplier-supplied0PASS
AX-2025-020384MKMMKM-2508-S3601Medutest2025-Q398.303.2591.9Supplier-supplied1FAIL
AX-2025-020385MKMMKM-2508-S3601Janoshik2025-Q398.503.6798.9Supplier-supplied1MARGINAL