Tuesday, 29 September 2026 09:23 AM
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A pass/fail endotoxin result carries no information unless the threshold behind it is stated, and for a laboratory compound or reagent no singular threshold exists. A New York supplier argues the measured value is what quantifies the endotoxin load and questions the validity of many certificates provided by suppliers today.
ALBANY, NY / ACCESS Newswire / September 29, 2026 / Crescent Bioresearch, a supplier of laboratory compounds/reagents, has published an analysis of how bacterial endotoxin is reported on certificates of analysis across the chemical supply industry, where purity is reported almost universally, identity is common and a numerical endotoxin value is virtually extinct. The analysis starts from the certificate itself, takes it apart, and follows the one measurement that many suppliers have replaced with a word.
The three parts of a certificate
A certificate of analysis for a laboratory reagent or chemical answers three separate questions, each by a specific method used to determine a separate metric. Apart from the chemical supply industry, USP holds these metrics under their own general chapters:
- USP <197A> - infrared spectroscopic identification. Is this the compound on the label?
- USP <621> - chromatography. How much of the material is the target compound?
- USP <85> - Bacterial Endotoxins Test. What is the endotoxin burden?
Identity, purity and endotoxin are three separate measurements of three unrelated failure modes. The first two arrive on a certificate as data: an infrared spectrum matched against a reference, and a purity percentage from a chromatogram. The third in most of the sector, arrives as a verdict. A research entity can read 99.7% and know what it means. It cannot read "pass" and know anything, because the number the verdict was supposedly measured against is not on the page, and for a laboratory reagent that number belongs to the research entity, not the supplier. The cost of that missing number is not theoretical: a 2024 report in Regenerative Therapy traced irreproducible cell-culture results to a purchased reagent whose endotoxin load had never been disclosed, and the investigators resolved it only by switching to a supplier that published the value.
"But what's the issue?" one may ask. "Is a pass/fail metric not enough?"
"The term 'pass/fail' has no defined meaning on a certificate, because the threshold it refers to is not stated," the company said. "Pass and fail are two words standing in for a number that was never published. Without that number, the result cannot be evaluated."
The non-existent endotoxin number
Many, if not all, current chemical and reagent suppliers are doing extensive testing. "What's the problem then?" one may wonder. There are few to no endotoxin reports publishing the numerical value, only a pass/fail metric that has no weight if the endotoxin burden is unknown and its measurement threshold arrives unstated.
But then it poses the question, why? One word: time.
Current third-party laboratories providing endotoxin testing alongside numerical values take a significant amount of time to deliver the value back to the chemical suppliers sending samples in. And because the market demands that chemicals and reagents be available quickly, the commercial incentive favors the laboratory that returns a pass/fail result in days over the one that returns a quantified value in weeks.
"The true numerical endotoxin value is absent from the majority of certificates being published, and when the absence is raised with suppliers, a clear explanation rarely follows," the company said. "The same research entities that will purchase these compounds are the same entities that will conduct studies determining whether or not they advance in the pharmaceutical industry. When you hold a medication bottle in your hand, that bottle was once a laboratory compound that only advanced because of the data that backed it."
Where the pass/fail verdict comes from
USP <85> is the compendial chapter for the Bacterial Endotoxins Test. In pharmaceutical manufacturing it is applied by calculating an endotoxin limit specific to each drug product; the chapter itself does not publish one number that covers every material. A pass/fail result on a pharmaceutical certificate carries meaning because that product-specific limit sits behind it.
This closely relates to the chemical supply industry and research institutes alike. If cell culture studies are being performed in the presence of microorganisms and the material being used has not been ruled out for bacterial endotoxins, the data produced cannot fully be attributed to a mechanism from the compound itself, thus creating insufficiency in the reported outcome. A certificate that reads "pass" with no stated threshold and no measured value has kept the form of the result and dropped the substance, and a research entity reading it is left with a word.
The numerical value matters most because research entities must devise their own acceptance criterion to use within their in vitro mode. The Regenerative Therapy investigators set 1.0 EU/mL for their cell-culture medium; a sole pass/fail verdict could not have told them whether a compound met it. Only a numerical value could.
Crescent Bioresearch publishes the numerical endotoxin value, rather than reducing it to a pass/fail metric. It leaves its certificates of analysis openly accessible, allowing research entities to apply the acceptance criterion appropriate to their own model.
What that looks like on a certificate
A laboratory that tests for an endotoxin load will set an assay sensitivity determining the lowest concentration the method can detect; the assay sensitivity is oftentimes mistaken for the numerical endotoxin value. If the certificate of analysis only shows the sensitivity calibration along with a pass/fail metric, the certificate has not provided an endotoxin value.
"Unverified compounds and incomplete testing reports remain common across the laboratory compound sector. It is vital for research entities nationwide to question their suppliers on the endotoxin value," Crescent Bioresearch said. "To the research entities that publish scientific literature, your data shapes the present and future of scientific understanding. The validity of your studies will suffice through maintenance of a strict standard for the material you work with."
METHODOLOGY
This analysis is based on USP General Chapters <85>, <197A> and <621>; and Uehara K, Oshiro E, Ochiai A, Takagi R, Yamato M, Kato A. "Lessons learned from contamination with endotoxin originated from the supplement in the cell culture medium." Regenerative Therapy, 2024;27:230-233. Market observations are drawn from a review of publicly posted certificates of analysis and third-party test findings within the laboratory compound/reagent sector, cross-referenced against Crescent Bioresearch's published lot-testing procedures.
ABOUT CRESCENT BIORESEARCH
Crescent Bioresearch is a supplier of laboratory compounds/reagents, founded around a framework of critical assessment. It works with research entities nationwide in pursuit of advancing and maintaining the integrity of scientific research as a whole through its extensive testing and transparency approach. Learn more about Crescent Bioresearch and its testing approach at https://crescentbioresearch.com/about.
Media Relations Department, Crescent Bioresearch, [email protected], https://crescentbioresearch.com/contact
SOURCE: Crescent Bioresearch