The tests that gate release, and the numbers we publish.
Nothing ships until it passes the assays below, run in our own QC lab at the Cambridge, Massachusetts facility where the lot was made, against acceptance criteria fixed before the lot is produced. The tables on this page use real, representative limits pulled from the catalog, not marketing language like “pharma-grade purity” standing in for a number.
We will not release a protein lot until the construct sequence is confirmed and both SDS-PAGE and RP-HPLC pass at ≥95–98% on the SKU datasheet. Purification and QC share our Cambridge facility.
| Test | Method | Representative release limit |
|---|---|---|
| Identity | Sequence-confirmed construct; UniProt / GenBank accession on the datasheet | Matches reference sequence |
| Purity | SDS-PAGE, reducing, Coomassie or silver stain | ≥ 95%, single-band criterion |
| Purity | RP-HPLC, single main peak | ≥ 95–98% depending on SKU |
| Molecular weight | SDS-PAGE against a calibrated ladder | Within the range on the datasheet (e.g. 17.2 kDa for recombinant human FGF2) |
Recombinant proteins target below 0.1 EU/µg. Media sit near 1 EU/mL. LAL on the filled bottle supplies EU/mL, and proteins also carry EU/µg because you dilute by weight.
Purity and potency diverge quietly on growth factors. We release cytokines and growth factors on ED50 from a responsive cell line, lot to lot against a working reference before shipment.
| Test | Method | Representative release limit |
|---|---|---|
| FGF2 (bFGF) | Proliferation of BALB/c 3T3 fibroblasts | ED50 0.1–0.6 ng/mL |
| EGF | Proliferation of BALB/c 3T3 fibroblasts | ED50 0.1–0.5 ng/mL |
| IGF-1 | Proliferation of MCF-7 cells | ED50 3–15 ng/mL |
Media and supplements are filtered at 0.1–0.2 µm and held for sterility. Live cultures also get mycoplasma. pH and osmolality match the targets on that formulation’s datasheet.
Chromatography media release on capacity, leakage, and CIP survival. DBC hits 10% breakthrough with a reference protein at set conditions. ELISA tracks ligand in the eluate. CIP time was validated on your functionalized lot.
| Test | Method | Representative release limit |
|---|---|---|
| Dynamic binding capacity | Reference protein loaded to 10% breakthrough (e.g. human IgG for Protein A media, 4 min residence) | e.g. 40 mg IgG/mL resin |
| Ligand leakage | ELISA against the ligand, measured in the eluate | e.g. 15 ng leached ligand per mg target protein |
| Clean-in-place tolerance | Exposure to the validated CIP reagent (e.g. 0.1 M NaOH) | ≤ 15 min contact, ≤ 10 cycles before re-qualification |
A unit of enzyme activity only means something with the definition attached, one supplier’s “unit” isn’t necessarily another’s. Every enzyme datasheet spells out its unit definition and the assay used to measure it lot-to-lot, so a titration you ran against a prior lot still means what you think it means.
| Test | Method | Representative release limit |
|---|---|---|
| Taq / hot-start Taq DNA polymerase | Primer-extension incorporation assay | 1 U incorporates 10 nmol dNTP into acid-insoluble material in 30 min at 74 °C |
| Phi29 DNA polymerase | Primer-extension incorporation assay | 1 U incorporates 0.5 nmol dNTP into acid-insoluble material in 10 min at 30 °C |
| Chemically competent cells | Heat-shock transformation with intact pUC19 | Transformation efficiency reported in CFU / µg DNA |
| T4 DNA ligase | Cohesive-end ligation of lambda/HindIII fragments, gel-based | 1 cohesive-end unit gives 50% ligation of HindIII-cut lambda DNA in 30 min at 16 °C in a 20 µL reaction. Not Weiss units. |
What’s actually on the CoA.
Catalog number, product name, and the specific lot number the certificate covers.
Each release assay run against that lot, the acceptance criterion and the measured value, side by side, not just a pass/fail stamp.
The date the lot was released, and the expiry or retest date it's good through.
The condition the result is only valid under, e.g. -80 °C frozen, or 2–8 °C protected from light.
The QA release statement for that lot, the sign-off that the batch record was reviewed and the material met spec.
A CoA is tied to the exact lot number on your vial or bottle, generated by the same Cambridge QC lab that ran the assays, never a catalog-wide typical value. Request a lot-specific CoA →
How a lot gets made
The expression, purification, and fill steps that lead into this QC.
Catalog →Every published spec
The purity, endotoxin, and activity figures, product by product.