Bramante
Account
Process

How a lot gets made, and what we keep on record.

Proteins, media, and resins leave our Cambridge, MA facility from documented runs. Read on for the process and what a lot number encodes.

Made in Cambridge, not shipped from across an ocean

Expression through fill stays in Cambridge. Overseas contract manufacturing and relabeling is not how these lots are made.

Short lead times

Made-to-order work quotes in days. An ocean crossing often adds six to ten weeks before customs.

No transoceanic cold chain

Cold chain stays on this continent. Often it stays in the same time zone.

Direct access to the people who made your lot

Write support@bramantebio.com and someone can walk over to the lot.

Made to order

Pack size and formulation changes are scheduling conversations in Cambridge.

Recombinant proteins: expression through fill
1

Express

Host per construct. E. coli, typically BL21(DE3). HEK293 or CHO when needed.

2

Capture

Most of the product volume leaves on the first affinity step matched to the tag or charge.

3

Polish

Orthogonal polish is SEC or IEX. Targets are host-cell protein, aggregate, and endotoxin.

4

Buffer exchange & filter

Exchanged into the final buffer on the datasheet, then 0.2 µm filtered before aseptic fill.

5

Fill & lyophilize

Aseptic vial fill, freeze-dry, stopper, and cake inspection. Reconstitution and storage are on the vial label and datasheet.

Cell culture media: formulation & filtration

Base media match a named recipe and the datasheet pH and osmolality. Sterilization is 0.1–0.2 µm membrane filtration.

Antibiotics and supplements follow the same filtration and fill path in smaller batches.

Filled lots stay in quarantine until sterility clears. Animal-cell media also wait on mycoplasma testing. Sterility testing is USP <71>-style.

Resins: functionalization & capacity qualification

Cross-linked agarose is the usual base matrix. Format is bulk resin or a prepacked column.

Ligand coupling is covalent. Density is controlled because density sets capacity.

We couple recombinant Protein A, anti-tag antibodies, lectins, or ion-exchange groups. Coupling density is controlled.

Capacity qualification loads a reference protein to 10% breakthrough. Dynamic binding capacity is reported in mg protein per mL resin.

Ligand leakage is measured by ELISA against the ligand. The datasheet publishes a ceiling.

CIP uses dilute NaOH in most cases. A cycle-count limit is on the datasheet. Validation uses that lot.

Fill/finish, labeling & lot numbering

After release testing, batches are filled and labeled. Cartons follow ambient, cold-pack, or dry ice on the datasheet.

Out-of-spec material is scrapped. It is not relabeled or blended down.

Every unit carries a lot number. That number opens the batch record for that vial. Request a lot-specific Certificate of Analysis from Documents.

  • Raw materials

    Lot numbers of the expression construct, resin, and formulation buffer components consumed in the run.

  • In-process checks

    Yield and purity between capture, polish, and fill.

  • Release QC

    Identity, purity, endotoxin, activity, and sterility on the filled material, as described on the Quality page.

  • Disposition

    Pass or scrap, signed against the acceptance criteria on file for that SKU.