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LAL · kinetic chromogenic · +$125 with core · $175 alone

Is there bacterial endotoxin in the vial?

Endotoxin is a piece of the outer wall of Gram-negative bacteria. It survives filtration and freeze-drying, and a very small amount injected causes fever and reactions. The Limulus amebocyte lysate assay detects it at a hundredth of an endotoxin unit per millilitre.

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LAL KINETIC CHROMOGENIC · VL-2026-[00404a]NOT DETECTED
Not detected
< 0.01 EU/mL · reconstituted in 1.0 mL
Positive product control
112% recovery ✓
Standard curve r
0.998 ✓
Illustrative readout — real lot spectra replace this when the registry opens.

How it works

  1. 01
    Reconstitute
    The vial contents are dissolved in a stated volume of endotoxin-free water — usually 1.0 mL — so the result can be read per millilitre or converted per milligram.
  2. 02
    React
    Sample is mixed with LAL reagent. Endotoxin triggers an enzyme cascade that releases a coloured product.
  3. 03
    Read kinetically
    A plate reader times how fast colour develops; faster means more endotoxin. The time is read against a standard curve run on the same plate.
  4. 04
    Check the controls
    A positive product control (sample spiked with known endotoxin) must recover 50–200%; if the sample inhibits the reaction, the result is invalid and we dilute and repeat.

What the result means — and what it doesn't

Not detected means below 0.01 EU/mL in the reconstituted sample with valid controls. The cutoff is always printed because it is the claim. Detected results give the value. Endotoxin not detected is one of the seal's four checks, and the only add-on the seal requires.

We will not say: "endotoxin free", "pyrogen free", or any claim about safety for injection. We report what the assay can see, at the limit it can see it.

Why another lab might report a different number

  • Reconstitution volume: the same vial read at 1 mL and at 5 mL gives numbers five-fold apart per mL. We print the volume.
  • Units: EU/mL versus EU/mg versus EU/vial. Convertible only if the volume and content are known.
  • Interference: some peptides inhibit or enhance the reaction; without a positive product control the number is unverified.
  • Gel-clot methods have a limit around 0.03–0.25 EU/mL and report pass/fail at that limit, not a value.

That's why every result here prints the method and the limit next to the number. The full science article on why tests vary.

Methods described are Vialidate's own and are published so results can be compared with other laboratories' on equal terms. Nothing on this page is medical advice. ISO 17025 accreditation in progress.