Assay Markets
Methodology

How the numbers are made

Methodology v1.6 · 18 October 2026

Source

Supplier list prices and product specifications are recorded daily from Cellbase (cellbase.com). Research records are indexed daily from Cellag (cellag.bio), published records only.

What a series is

One product variant from one source. Each pack size is its own series. A series begins on the first clean observation of that variant, and change is measured only within that series.

What counts as an observation

The supplier's own list price, as recorded on the source, captured once a day, recorded as observed. A price of zero is a listing state, not a price, and is not recorded. Missing days stay missing; the archive is never back-filled.

Prices

The archive records each price as observed and never overwrites it. Prices in USD.

Normalisation (method v1)

Per-litre and per-milligram figures are calculated at display time from the recorded price and the pack size. Cell lines, scaffolds and equipment are not normalised. The method version changes only by notice on this page.

Class specifications

A class figure is computed only from listings of the same molecule, normalised to the same unit, at the pack sizes the class specification names; within a class each vendor contributes one figure, its cheapest in-spec per-unit price, and the class median and range are taken over those vendor figures. A class figure is published only when at least three vendors contribute; with fewer, the class shows no figure. A price range is stated only for a class; elsewhere, figures are given per listing with their pack size.

DMEM — /L — 500 mL–1 L
DMEM/F-12 — /L — 500 mL–1 L
DPBS / PBS — /L — 500 mL–1 L
FBS — /L — 500 mL–1 L
FGF-2 / bFGF — /mg — 1 mg
EGF — /mg — 1 mg
IGF-1 — /mg — 1 mg

Engineered analogues, multi-product kits, concentrates and dissociation reagents are recorded and browsable, but are not part of a class.

Products outside a class specification are recorded and browsable but do not enter the class figure. Specifications change only by notice on this page.

Gaps and corrections

Observations are recorded daily. If a source is unavailable on a given day, no observation is recorded for that day and the gap remains in the series. Gaps are never filled, interpolated or back-dated.

A series with a gap displays its last observed figure and the date that figure was observed. No figure is carried forward as if it were current.

Observations are never revised after publication. Where an error in an observation is identified, a corrected observation is recorded as a new entry, the original remains in the record, and the correction is noted in the change history below.

Scope

Growth media, cell lines, reagents and scaffolds make up the index. Equipment and uncategorised listings are recorded and browsable but excluded from index counts.

Categories follow Cellbase's product roles.

Immutability

The archive is append-only. Observations are never edited or deleted. Data found to be unreliable is quarantined — excluded from every published view — never removed.

Specifications

Vendor-published product specifications are recorded alongside prices. They are stored as published, versioned when they change, and never alter a recorded price.

Ingredient links

An ingredient named in a research record is linked to a listing only where Cellbase's reviewed pairing of products to ingredients confirms it. Engineered analogues and kits are never linked to the base ingredient.

Citation

"Assay Markets, [input name], observed [date], assaymarkets.com/series/[id]." Third parties citing the data should include the observation date.

Change history

This section records changes to the published method only — rule changes, spec changes, corrections. It is not a site changelog and does not carry product or interface changes.

  • 18 October 2026 — Ingredient links and categories now come from Cellbase's reviewed product data.
  • 18 October 2026 — Immobazyme's engineered FGF-2 fusion protein is excluded from the FGF-2 / bFGF class as an engineered analogue.
  • 5 October 2026 — Each input's price is now the supplier's own list price, published in USD. From this date, every figure is fixed on the day it is observed and is never revised. Change figures reflect the supplier's own price. Observations from 24 September 2026 have been restated once on this basis; earlier observations keep their original basis.
  • 30 September 2026 — Cellbase prices are now read directly from Cellbase's catalogue rather than its public product feed. Prices and product coverage were verified identical before the switch.
  • 16 September 2026 — Analogues and kits separated. Engineered analogues and kits are no longer linked to the base ingredient; thirty-eight such links were withdrawn. Price ranges are stated only for classes.
  • 16 September 2026 — Minimum stated. A class figure requires at least three contributing vendors. No published class figure changed.
  • 16 September 2026 — Ingredient links reviewed. Automatic links now require the full ingredient name in the product name; other links are reviewed by hand. Thirty-three links that joined an ingredient to a different product were withdrawn.
  • 15 September 2026 — Molecule matching corrected. Product names are normalised for punctuation before matching, and FGF-2 / bFGF now recognises bFGF2 and Fibroblast Growth Factor 2. A vendor previously omitted from the class is now included.
  • 15 September 2026 — Exclusions defined. Engineered analogues (FGF2-G3, thermostable FGF-2), multi-product kits, concentrated buffers (for example 10×) and dissociation reagents are excluded from their classes. DMEM/F-12 requires DMEM in the product name; Ham's F-12 on its own is a different medium and is not part of the class.
  • 15 September 2026 — Classes added: EGF and IGF-1, per mg, 1 mg pack exactly. EGF excludes VEGF and HB-EGF. IGF-1 excludes IGF-1 LR3 and IGF-2.
  • 15 September 2026 — FGF-2 / bFGF pack-size band narrowed to 1 mg. The previous open-ended band admitted bulk packs that no other vendor offered, so the class low reflected pack size rather than market structure.
  • 14 September 2026 — Class specifications introduced. Class figures are computed only from in-spec observations; one figure per vendor.
  • 28 August 2026 — Recording begins.