BET Products
Get to know the LAL Test, Pioneered by ACC
Bacterial endotoxin testing (BET) is critical to ensuring the safety of many biopharmaceutical products. With rapid innovation and the development of cutting-edge therapies and new treatment approaches, companies require flexible and dependable endotoxin testing methods to expedite time to market. Precise testing methods help our customers deliver safe, life-saving treatments to patients, ultimately advancing healthcare and global safety standards.
The Limulus amebocyte lysate (LAL) test is used to detect and quantify bacterial endotoxins, which are toxins from the outer membrane of gram-negative bacteria. These endotoxins can cause severe immune reactions, which is why vaccines, injectable drugs, biological products, and medical devices must be tested before they are delivered to patients.
The key component of LAL reagents is derived from the blood cells (amebocytes) of the horseshoe crab, Limulus polyphemus. These reagents contain proteins involved in the blood clotting mechanism, which is triggered by endotoxins. LAL endotoxin detection tests are primarily used to ensure product safety in pharmaceutical manufacturing, renal dialysis centers, and other critical applications.
For details on compliant LAL test methods in the United States, users should consult the current revision of Chapters <85> of the United States Pharmacopeia (USP) endotoxin test requirements and equivalent chapters in the European Pharmacopoeia (Chapter 2.6.14) and the Japanese Pharmacopoeia (General Tests, No. 4.01).
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How to Choose an LAL Test Method
When deciding which LAL test method to use for endotoxin testing, consider the following:
What is the available budget?
If the budget is limited, the gel-clot method is the least expensive as no optical reader is required.
What type of product or sample is going to be tested?
The gel-clot method may be the method of choice for opaque samples, suspensions, or colored samples, though dilution of the sample may necessitate the use of the kinetic methods.
What test sensitivity is required?
The kinetic photometric methods (chromogenic and turbidimetric) offer the greatest sensitivity, allowing detection of low bacterial endotoxin concentrations and greater dilution of samples, which is important for overcoming interference.
Is quantitative analysis desired?
The chromogenic and turbidimetric endotoxin testing methods utilize software to quantify your test results. The gel-clot method is a simple, positive/negative, low-start-up-cost alternative.
Get Bacterial Endotoxin Testing Advice From the Experts
Ready to elevate your bacterial endotoxin testing with the most reliable LAL reagents and support? Get expert guidance from the specialists at ACC. Whether you need help selecting the right product or have questions about test methods, our experienced team is here to support you every step of the way.
Contact us today and ensure your testing is accurate, compliant and efficient.
Overview of Testing Procedures
The following section summarizes the procedures/steps to be taken to perform routine product release testing of a sample in a regulated environment. In an unregulated environment, or when testing for informational purposes only, follow the procedures described under Product Characterization
Qualification of Reagent, Technician and Laboratory
The reagent must be tested to ensure that it is performing to specification, technicians must be qualified to perform the test, and the absence of significant day-to-day or inter-technician variability in the laboratory should be documented. This requires tests using endotoxin standards only, not samples.
Product Characterization
Samples should be characterized for endotoxin contamination and/or potential interference. Characterization is not a regulatory requirement, but it is important to develop a test method that can be validated to demonstrate the absence of interference. It is typically performed by testing a series of dilutions of the sample without and with a known amount of added endotoxin (Positive Product Control or PPC). The purpose of the PPC is to indicate that added endotoxin is appropriately detected and that the sample does not interfere with the test. From the results of characterization testing, a product dilution (and possibly product treatment) is selected for validation of the test (see below). The endotoxin limit for the product must be detectable at the dilution selected.
Test for Interfering Factors (Validation)
Inhibition/Enhancement testing is performed to validate the test for the particular sample type. It is accomplished by demonstrating, with three lots of product, that endotoxin added to the sample in PPCs can be readily detected within the required limits.
Routine Testing
Routine testing is conducted at the validated dilution and includes a parallel PPC to control for interference. Tests should also include negative controls and appropriate standards. A minimum of three units per lot of drug product should be tested, with samples taken at the beginning, middle, and end of the production run. For medical devices, aqueous extracts of up to 10 units are tested, usually after pooling.