Kidney proximal tubule models: you can buy every part except the tubule

The short answer: the cells are cheap and public, the plates are cheap and public, and the tubule is not for sale.

This is the clearest example on this site of a category where every physical input carries a live list price and the assembled object carries none. Two suppliers publish live prices for human renal proximal tubular epithelial cells. A third publishes live prices for perfused microfluidic culture plates. No supplier surveyed sells a released, barrier-verified human proximal tubule model with a stated TEER or transporter acceptance criterion, at any price. That is the whole shape of the market and it should determine how you plan the work.

The proximal tubule is the nephron segment that performs most reabsorption and absorbs most drug-induced injury, which is why it is the renal model almost every buyer actually wants. It is also why the gap is expensive: the thing that makes a proximal tubule model useful is not that the cells are renal, it is that the epithelium polarises and expresses functional transporters. Buying cells buys you neither. It buys you the possibility of both.

What is purchasable today, plainly

The supplier we could not check

Honesty requires this section rather than a silent omission.

Newcells Biotech is the named specialist in this category and appears in search metadata and in published microphysiological systems literature as offering kidney nephron models including a proximal tubule product plus assay services. We could not verify any of that. Automated retrieval of the site was blocked across repeated attempts during our supplier coverage, and a direct fetch on 2026-09-01 failed with a TLS certificate validation error.

So: no product, no price, no specification and no willingness to supply is asserted here, in either direction. It is entirely possible that they sell exactly the thing this page says nobody sells. It is equally possible they do not. What we can say is that a buyer cannot evaluate them from the open web on the date shown, which is itself a procurement fact. If this category matters to your programme, contacting them directly is a reasonable first action and we would treat any answer they give as new evidence.

Everywhere else on this page, “no supplier sells this” means “no supplier we could actually read sells this”.

The parts, costed honestly

Because the model is unpriced, the only defensible arithmetic runs on the parts. Here is a component bill for a small first-article programme. Every figure below is a live vendor list price captured 2026-09-01 for a component. None of them is a price for a proximal tubule model, and the total is not a quotation for one.

The shape of that table is the argument. Roughly one to three thousand dollars of publicly priced parts sits in front of an unbounded, unpriced work package, and the unpriced package is the one that decides whether you get a tubule or a monolayer.

Why the age grade line matters more than the price line

One supplier lets you pick adult, fetal or neonatal tubular cells at a published price. That looks like a convenience feature. It is not.

Fetal, neonatal and adult renal tubular cells differ in transporter expression. If your programme depends on a named efflux or uptake transporter, and most nephrotoxicity and renal clearance programmes do, then the age grade you tick in a shopping cart is a scientific decision made at the point of purchase, weeks before anyone measures anything. The price difference across the range is a few hundred dollars. The consequence of choosing wrong is a study that cannot answer its question.

Put the age grade in the specification, not in the order form.

What the literature says the model can do

This section exists so you can judge whether a quote you receive is ambitious or ordinary. These are published findings under the specific conditions each paper describes, not product specifications and not transferable to a different device.

Perfused proximal tubule models replicate polarised function. A microphysiological model of human kidney proximal tubule function reported a 3D flow-directed system that replicates the polarity of the proximal tubule, expresses appropriate marker proteins, and exhibits biochemical and synthetic activities together with secretory and reabsorptive processes associated with proximal tubule function in vivo. That is the capability bar. It has been met in the literature.

Perfused tubules can be maintained for months. Bioprinted 3D convoluted renal proximal tubules embedded in extracellular matrix within perfusable tissue chips were maintained for greater than two months, with significantly enhanced epithelial morphology and functional properties relative to the same cells grown in 2D with or without perfusion, and with dose-dependent barrier disruption on introduction of the nephrotoxin cyclosporine A. Two things follow. First, longevity is not the blocker. Second, perfusion is doing measurable work, the same cells behave differently, so a static insert model and a perfused model are not interchangeable answers to the same question.

Transporter interaction screening and polarisation-dependent toxicity have both been demonstrated in 3D microfluidic renal proximal tubule configurations, as has nephrotoxicity and kidney transport assessment on perfused proximal tubules, and a multicompartment proximal tubule-on-a-chip replicating cell polarisation-dependent cisplatin toxicity. Kidney proximal tubule-on-a-chip for drug transport and nephrotoxicity assessment dates to 2013.

So the science is not the gap. The gap is that none of that capability is sold as a released object with a number attached to it.

The specification that makes a quote checkable

If you go out to quote for this as a development programme, which is the only route available, the following fields are what separate a comparable quote from an incomparable one:

• Geometry. A perfusable tubule in a microfluidic lane, or a flat epithelium on a permeable insert. These are different models with different costs and different failure modes.
• Cell source and age grade, adult, neonatal or fetal, and the reason for the choice, because it changes transporter expression.
• Primary versus immortalised versus iPSC-derived. Immortalised lines are cheaper and more reproducible and frequently lose the transporter you care about.
• Whether an endothelial or interstitial compartment is required alongside the tubular epithelium. This roughly doubles the seeding complexity.
• Named transporters that must be functionally demonstrated, not merely expressed. Write the word “functionally” into the RFQ. Expression by immunostaining is not transport.
• Barrier acceptance criterion, TEER value or permeability coefficient for a named tracer, and the method and electrode configuration used to measure it. TEER values are not comparable across methods and a quote that does not state the method has not agreed to anything.
• Flow regime and shear stress if a perfused configuration is specified.
• Number of tubules or chips and the replicate structure.
• Whether you already own a platform the model must run on, because that decision may already be made for you.
• What happens to units that fail the acceptance criterion, and who pays for them.

That last point is where the money actually sits. In a category with no released product, the commercial question is not what a tubule costs. It is who owns the failure when the epithelium does not polarise.

Our position

We broker this. Every material delivered through us is made by a named partner and labelled as partner-manufactured.

What we can do here is narrow and we would rather state it than oversell it. We can consolidate cells, plates and medium onto one order at published prices, and we can hold a written barrier and transporter acceptance criterion in front of several contract laboratories until one of them either accepts it or explains why not. What we cannot do is produce a supplier who already sells this object, because on the evidence available on 2026-09-01 there is not one.

If you have a tissue culture capability and a perfusion platform, the honest recommendation is to buy the parts and build it, using the age grade decision and the functional transporter wording above to avoid the two failure modes that cost the most. If you do not, send us the specification and we will find out in writing who will hold the acceptance criterion, including from the one supplier in this category we could not read.