{"id":2874,"date":"2026-08-21T21:12:27","date_gmt":"2026-08-21T20:12:27","guid":{"rendered":"https:\/\/seamlessbio.de\/?p=2874"},"modified":"2026-08-21T21:12:29","modified_gmt":"2026-08-21T20:12:29","slug":"xeno-free-serum-free-animal-component-free-difference","status":"publish","type":"post","link":"https:\/\/seamlessbio.de\/de\/xeno-free-serum-free-animal-component-free-difference\/","title":{"rendered":"Xeno-Free vs Serum-Free vs Animal"},"content":{"rendered":"

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August 2026 \u00b7 6 min read<\/em><\/p>\n

Xeno-free. Serum-free. Animal component-free. Chemically defined. These four terms appear in almost every cell therapy protocol \u2014 and they are not synonyms. Using the wrong one in a regulatory document or manufacturing protocol can cause confusion, delays, and compliance questions. Here is exactly what each means.<\/p>\n

The four terms \u2014 definitions<\/h2>\n

Serumfrei<\/h3>\n

Definition:<\/strong> No serum (FBS, human serum, or any other whole serum) is present in the medium formulation.<\/p>\n

What it does NOT exclude:<\/strong> Other animal-derived components \u2014 BSA, bovine transferrin, bovine insulin, trypsin, bovine pituitary extract, animal-derived growth factors. A medium can be serum-free while containing multiple bovine proteins.<\/p>\n

Example:<\/strong> DMEM + 4 mg\/mL BSA + 10 \u00b5g\/mL bovine transferrin + 10 \u00b5g\/mL bovine insulin = serum-free but NOT animal component-free.<\/p>\n

Xeno-frei<\/h3>\n

Definition:<\/strong> No components derived from a species other than the species being cultured. For human cell culture \u2014 no bovine, porcine, murine, or other non-human animal-derived components. Human-derived materials (human albumin, human transferrin, human platelet lysate) are acceptable.<\/p>\n

What it does NOT exclude:<\/strong> Human-derived biological materials. hPL, human AB serum, recombinant human albumin (rHSA), recombinant human transferrin, and human plasma-derived components are all xeno-free for human cell culture.<\/p>\n

Example:<\/strong> DMEM + 5% human platelet lysate + rHSA + OsrhTF = xeno-free but NOT serum-free (hPL is serum-equivalent) and NOT animal component-free (hPL is a biological material).<\/p>\n

Animal Component-Free (ACF)<\/h3>\n

Definition:<\/strong> No components derived from any animal source \u2014 including human donors. All components are either synthetic or produced by microbial\/plant recombinant expression.<\/p>\n

What it excludes:<\/strong> FBS, human serum, hPL, BSA, bovine transferrin, bovine insulin \u2014 and also rHSA if produced in a mammalian expression system. Plant-expressed rHSA (e.g. OsrhHSA from rice) and microbially-expressed components are ACF.<\/p>\n

Example:<\/strong> Chemically defined basal medium + OsrhHSA (rice-expressed) + OsrhTF (rice-expressed) + recombinant human insulin (E. coli-expressed) + recombinant cytokines = ACF.<\/p>\n

Chemically Defined<\/h3>\n

Definition:<\/strong> Every component is a purified, identified chemical entity with a known molecular structure and concentration. No undefined biological mixtures.<\/p>\n

What it excludes:<\/strong> All whole sera (FBS, human serum), hPL, and any undefined biological extract. Recombinant proteins are chemically defined if they are fully characterised.<\/p>\n

What it includes:<\/strong> Amino acids, vitamins, inorganic salts, recombinant cytokines, recombinant growth factors, recombinant albumin, synthetic lipids \u2014 all at defined concentrations.<\/p>\n

The relationship between the terms<\/h2>\n\n\n\n\n\n\n\n\n\n
Medium type<\/th>\nSerum-free?<\/th>\nXeno-frei?<\/th>\nAnimal component-free?<\/th>\nChemically defined?<\/th>\n<\/tr>\n
DMEM + 10% FBS<\/td>\nNein<\/td>\nNein<\/td>\nNein<\/td>\nNein<\/td>\n<\/tr>\n
DMEM + 5% human AB serum<\/td>\nNein<\/td>\nYes (for human cells)<\/td>\nNo (human-derived)<\/td>\nNein<\/td>\n<\/tr>\n
DMEM + 5% hPL + rHSA<\/td>\nNo (hPL is serum-equivalent)<\/td>\nJa<\/td>\nNein<\/td>\nNein<\/td>\n<\/tr>\n
DMEM + BSA + bovine transferrin<\/td>\nJa<\/td>\nNein<\/td>\nNein<\/td>\nNein<\/td>\n<\/tr>\n
DMEM + rHSA + OsrhTF + recombinant insulin<\/td>\nJa<\/td>\nJa<\/td>\nJa<\/td>\nYes (if all components defined)<\/td>\n<\/tr>\n
mTeSR1 (StemCell Technologies)<\/td>\nJa<\/td>\nNo (contains BSA)<\/td>\nNein<\/td>\nNein<\/td>\n<\/tr>\n
TeSR-E8 (StemCell Technologies)<\/td>\nJa<\/td>\nNo (contains BSA)<\/td>\nNein<\/td>\nPartially<\/td>\n<\/tr>\n<\/table>\n

Which term does your application actually require?<\/h2>\n

ATMP manufacturing (MSC, CAR-T, NK cells)<\/h3>\n

Required: Xeno-free at minimum.<\/strong> EMA’s Advanced Therapy Guidelines explicitly state that xeno-free conditions should be used for clinical-grade human cell manufacturing to eliminate the risk of xenogenic immunogenic reactions in patients. Animal component-free is preferred for the highest regulatory confidence. Chemically defined is the ultimate goal but not yet universally achievable for all cell types.<\/p>\n

Research in human cell biology<\/h3>\n

Serum-free is usually sufficient.<\/strong> Most researchers describing their medium as “serum-free” mean they are not using FBS \u2014 they may still use BSA or bovine transferrin without specific concern. This is scientifically acceptable for non-clinical research but should be accurately described in publications.<\/p>\n

GMP manufacturing \u2014 IND\/BLA submissions<\/h3>\n

Animal component-free is increasingly expected.<\/strong> Regulatory reviewers for cell therapy INDs now routinely ask about all animal-derived raw materials \u2014 not just serum. A manufacturing process using bovine-derived BSA or transferrin requires the same TSE\/BSE documentation as FBS. Using recombinant human alternatives (rHSA, OsrhTF) eliminates this documentation burden entirely.<\/p>\n

Process development and screening<\/h3>\n

Any level may be appropriate.<\/strong> Start with serum-containing conditions for feasibility; transition toward xeno-free or ACF as the process matures toward clinical application. Changing the medium formulation at any stage requires re-validation \u2014 plan transitions early.<\/p>\n

SeamlessBio products for each category<\/h2>\n\n\n\n\n\n\n
Category<\/th>\nProdukt<\/th>\nAvailable from SeamlessBio<\/th>\n<\/tr>\n
Xeno-free serum equivalent<\/td>\nHuman AB Serum, Human Platelet Lysate (hPL)<\/td>\nHuman Serum Portfolio<\/a><\/td>\n<\/tr>\n
Xeno-free + ACF albumin<\/td>\nrHSA (OsrhHSA, rice-expressed)<\/td>\nrHSA<\/a><\/td>\n<\/tr>\n
ACF iron delivery<\/td>\nOsrhTF (recombinant human transferrin, rice-expressed)<\/td>\nOsrhTF<\/a><\/td>\n<\/tr>\n
Serum-free carrier (non-human)<\/td>\nBSA Standard, Low Endotoxin, Fatty Acid Free<\/td>\nBSA Portfolio<\/a><\/td>\n<\/tr>\n<\/table>\n
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Weiterf\u00fchrende Literatur:<\/strong><\/p>\n