Fibroblasts and keratinocytes: age grade is a specification, and most purchase orders leave it blank

Order “human dermal fibroblasts” and you will receive human dermal fibroblasts. What you will not have specified is whether they came from an adult, a neonate or a fetus, and those three populations proliferate at different rates, deposit matrix differently, and senesce on different timescales.

At Cell Applications the age grade is selectable at order. If you do not select it, the supplier resolves the question in whichever direction their stock sits. The substitution is invisible on delivery, invisible on the certificate of analysis, and becomes visible about six weeks later when your data does not match the literature you were comparing against.

Neonatal foreskin fibroblasts are the default in a very large body of published skin work, which makes them the easiest cells to compare against the literature and one of the worst proxies for adult skin biology. Both of those statements are true simultaneously, and which one matters depends on what you are claiming.

The price table

Phenion publishes the only complete public price list found anywhere in the reconstructed tissue market: a downloadable document covering models, cells, media and accessories, valid from 01.01.2024, produced at Henkel’s Düsseldorf site. Most of this market quotes. One supplier publishes, and it is worth using as a reference point even if you buy elsewhere.

Note that the euro and dollar figures above are not comparable without a conversion rate and a shipping origin. They are reproduced as published.

The volume discount nobody uses

Buried in the Phenion price list is a published discount structure:

These are small percentages, and that is exactly why they get ignored, but they apply to the whole order, and in this category the thresholds are easy to cross. A skin model programme buying fibroblasts, keratinocytes, feeder cells and media across a quarter is very often already spending above EUR 3,000 without noticing, because the spend arrives as five separate small purchase orders placed by three people.

Consolidating a quarter’s orders into one is worth 5 to 9 percent for no scientific compromise whatsoever. It is the cheapest saving on this page and it requires nothing but a purchasing calendar. The same logic applies to media: the fibroblast medium at EUR 55 per 250 mL and the keratinocyte medium at EUR 85 per 250 mL are the kind of small repeat orders that get placed individually and never counted toward a threshold.

Age grade, and what the substitution actually costs you

The three grades are not quality tiers. They are different biology.

Fetal. Fastest proliferating, most matrix deposition, latest senescence. The most forgiving cells to culture and the furthest from adult skin.

Neonatal. The published-literature default, particularly foreskin-derived. Fast, robust, well characterised. Phenion’s catalogued fibroblasts and keratinocytes are both human foreskin, juvenile, supplied at passage 1, which is an unusually precise disclosure.

Adult. Slower, senesces earlier, deposits matrix differently, and is the only grade that supports a claim about adult skin. If your endpoint is ageing, wound repair in adults, or an adult clinical comparison, this is the specification.

The literature makes the age dependence concrete rather than theoretical. A 2026 study in Cell Communication and Signaling documents age-related changes in calcium ion influx and efflux capacity of human dermal fibroblasts (PMC12983909), donor age changes a basic cellular property, not merely a growth rate.

Culture itself is a second variable on top of donor age. Single-cell RNA sequencing of dermal fibroblasts published in iScience in 2026 demonstrates culture-induced changes and variable persistence of subpopulations (PMC13123497). The population you have at passage six is not the population you received at passage one, regardless of grade.

And matrix behaviour, which is what a fibroblast is usually bought for in a skin model, is modulable: IGF-1 has been shown to increase collagen deposition by dermal fibroblasts in a tissue engineering context (PMC13257193). Which means matrix output is a function of the medium as well as the donor, and comparing your construct to a published one requires matching both.

The procurement rule: write the age grade on the purchase order every time, even when you do not think you care. It costs nothing and it removes an unrecorded variable from your methods section.

Matched donors: the specification that is available and almost never requested

If you are building a full-thickness skin model, you are combining keratinocytes and fibroblasts. In most laboratories, those come from two different people.

That is a confound, and it is avoidable. Phenion catalogues fibroblasts and keratinocytes from the same tissue type, human foreskin, juvenile, passage 1, as parallel SKUs. Several suppliers, including Cell Applications, ScienCell, iXCells and Cook MyoSite, advertise custom isolation of different cell types from the same donor as a service. The route is set out in the matched donor material datasheet.

The reason it matters is that keratinocyte-fibroblast crosstalk is the mechanism a skin equivalent depends on. Published work on self-assembly of keratinocytes and fibroblasts into 3D spheroid structures (PMC13072246) illustrates how much of the resulting architecture emerges from the interaction between the two populations rather than from either alone. An unmatched pair introduces donor-donor immunological and genetic difference into the exact interaction you are studying.

Ask the question in the enquiry. “Can you supply keratinocytes and dermal fibroblasts from the same donor, and at what price and lead time?” Most buyers never ask, so most suppliers never offer. No supplier surveyed publishes a matched pair as a standard catalogue item with a price, so this is a quote, but it is a normal commercial request rather than a research collaboration.

Keratinocytes: donor site and passage matter more than they appear to

Keratinocytes are the more fragile purchase and the one where specification gaps bite faster.

Passage at ship is close to decisive. Keratinocytes have limited proliferative capacity and lose differentiation competence with passage. Phenion states passage 1 explicitly, which is unusually early and unusually clear. A supplier who says “low passage” without a number is not giving you a specification. Ask for the integer.

Anatomical site is not cosmetic. Foreskin keratinocytes, adult breast skin keratinocytes and gingival keratinocytes behave differently. Work on gingival keratinocytes showing that fibre architecture directs proliferation and differentiation (PMC12896891) is a reminder that both the donor site and the substrate the cells sit on are variables in the differentiation outcome. If your model is oral mucosa, dermal keratinocytes are the wrong purchase; that category is covered in oral, gingival and mucosal models.

Feeder cells are a separate SKU and a separate decision. Phenion catalogues feeder cells from human foreskin fibroblasts at EUR 580. If your keratinocyte protocol is feeder-dependent, that is a line item, and if you are trying to run feeder-free, that is a protocol change with consequences for comparability against published data.

Buy the cells, or buy the finished model

The decision that should be made before any cell is ordered.

Buy cells and build when the model construction is part of the science, when you need a donor, genotype or disease state that no finished model offers, when you need many constructs at marginal cost, or when you intend to modify the architecture.

Buy the finished model when you need a validated tissue for a standardised assay on a schedule. For regulatory skin work in particular, the model is the validated unit and building your own means validating your own. The economics and the vendors are in reconstructed human epidermis, the price comparison is in the RhE price comparison, and the regulatory framing is in replacing animal testing for skin.

The honest summary: building your own skin equivalent from EUR 500 fibroblasts and EUR 580 keratinocytes looks cheap against a finished model, and the cell cost is genuinely a small fraction of it. What the finished model price includes is weeks of culture, an air-liquid interface transition that has to work, batch-to-batch consistency, and in the regulated case a validation package. Those are the expensive parts, and they do not appear on this page’s price table.

QC checklist

• Lot-specific certificate of analysis, reviewed before you commit.
• Age grade stated as an integer age or an explicit grade, in writing on the order and on the certificate.
• Passage number at ship, as a number.
• Guaranteed remaining population doublings where the supplier publishes one, and the medium the guarantee is conditional on.
• Anatomical site of the donor tissue.
• Donor demographics, age, sex, ethnicity where relevant to the claim.
• Disease state where a phenotype is the requirement, such as Type 2 diabetic donors.
• Post-thaw viability specification and the assay used.
• Itemised pathogen panel by agent name, not a “tested” claim.
• Mycoplasma and sterility release testing with method named.
• For matched pairs: documentary confirmation that both cell types came from the same donor, with an identity method named. A supplier’s assurance is not a specification.
• Whether feeder cells are required by the keratinocyte protocol, and whether they are included.
• Shipping format and receiving procedure.

Specification checklist for a fibroblast or keratinocyte quote

• Cell type: dermal fibroblast, keratinocyte, or feeder, listed separately, each with its own specification.
• Age grade, written explicitly. This is the field this page exists to make you fill in.
• Anatomical site, stated rather than assumed.
• Matched donor requirement: whether the fibroblasts and keratinocytes must come from the same individual, and your acceptance that this is a quote rather than a catalogue item.
• Passage at ship and the doublings your protocol requires, worked out at your split ratio before the enquiry.
• Disease state or donor phenotype where it is the point of the experiment.
• Media package, fibroblast medium, keratinocyte medium, or both, and whether it is quoted.
• Total order value across the quarter, aggregated, so published volume discount thresholds are actually crossed rather than narrowly missed.
• Currency and shipping origin, since the two published price sets in this category are in different currencies from different continents.
• Whether the destination is a self-built model or a component of one, because that changes whether you should be buying cells at all.
• Licence terms for anything downstream that will be sold rather than published.

Where to go next

The datasheet, unit, lead time and QC scope, is at dermal-fibroblasts-and-keratinocytes. If a finished tissue is the better answer, reconstructed human epidermis covers what ships and the price comparison does the per-unit arithmetic. The supplier landscape for primary human cells generally is in primary human cell suppliers.

How we can help

Three things here are worth having someone else chase: getting the age grade written onto the order and onto the certificate of analysis, getting a matched-donor fibroblast and keratinocyte pair quoted when no supplier lists one, and aggregating a quarter’s small orders so a published volume discount threshold is actually crossed.

Tell us the model you are building, the donor constraints and the timeline, and we will source quotes with the age grade and passage stated, ask the matched-donor question, and tell you honestly if the finished tissue is cheaper than what you are proposing to build.