Service Center
Customer Portal
Testing Services
Medical Devices
Pharmaceuticals
Tissue Testing
Natural Products
Search
Test Question
Testing Services > Tests > Bacterial Endotoxin Test (LAL)

Bacterial Endotoxin Test (LAL)

The Bacterial Endotoxin Test (BET) is an in vitro assay for detection and quantitation of bacterial endotoxin. This test is also commonly referred to as the Limulus Ameboycte Lysate (LAL). This test is performed on lot releases for medical devices and pharmaceutical products in order to meet the label claim as “non-pyrogenic”, and is performed on all medical devices with direct or indirect blood, lymph or cerebrospinal fluid contact. All parenteral drug products must also be tested for Bacterial Endotoxin. The LAL test can also be used as a process monitor to ensure that the product or process does not contribute endotoxin, which is a residue of Gram negative bacteria. This helps to demonstrate bioburden control. The test can be performed by the kinetic turbidimetric, kinetic chromogenic or gel-clot test methodologies. All testing meets the requirements set forth in the USP Chapter 85 and Chapter 161, as well as the FDA BET Guidance document (1987), AAMI ST 72:2002, and European Pharmacopeia 2.6.14
 
Nelson Laboratories is a leader in the industry for BET Testing with over 25 years of experience. We know and understand the test criteria because we are extensively involved in the writing of the standards. We can provide the test results within the same day of sample receipt, if requested, so that there is minimal delay in release of product. Routine testing, without special request, can be completed in as little time as the following day from sample receipt. Special projects involving the development of the test method are done thoroughly and with expertise and quality to optimize the routine testing of the product. Validation and recovery studies are performed with a process that has demonstrated to be effective and compliant. Our team is also available to help with failure investigations and evaluation of the manufacturing process.

SOLID SAMPLE EXTRACTIONS: Extraction of the devices is performed using non-pyrogenic water. The extraction process involves flushing and/or washing the devices with an appropriate amount of extract liquid that completely immerses or flushes the device. USP Chapter 161 Extraction Parameters are followed for fluid pathway extractions. Immersion extractions are performed by washing the devices at 37-40°C for 40-60 minutes with intermittent swirling on an orbital shaker.

TEST PROCEDURE:  A BET test involves testing the liquid sample or the sample extract with Limulus Amebocyte Lysate (LAL). BET is an aqueous extract of the blood cells of horseshoe crabs which forms a clot or change in color, depending on the technique, in the presence of bacterial endotoxin. The test sample is compared to a standard series of Control Standard Endotoxin (CSE) dilutions. The endpoint or reaction times of these dilutions are used to calculate the amount of endotoxin present in the sample. All tests are performed in at least duplicate. A positive control of the sample and negative control using non-pyrogenic water are also performed. An initial validation on 3 lots must be performed to validate this method of testing for a given product.

SCORE: The endotoxin limit for devices used intrathecally (cerebrospinal fluid contact) is 2.15 EU/device (Endotoxin Units/device). The limit for other medical devices is 20.0 EU/device. For drugs and liquids, refer to the BET Guideline published by US FDA (December 1987).
“Nelson Labs is the best laboratory that I’ve worked with.”

Tal , International Regulatory Affairs Manager , Medical Device Manufacturer



SAMPLE REQUIREMENTS:  USP bacterial endotoxins testing requires 3% of the production lot with a minimum of 3 and maximum of 10 devices to be pooled and tested. The FDA guideline allows the testing of 2 devices for lot sizes under 3.

SOLID DEVICES: 3% of the production lot (minimum of 3 and maximum of 10 devices)
LIQUID SAMPLES: 1 ml
POWDER SAMPLES: Enough to reconstitute to a minimum of 1 ml
Devices may be sterile or non-sterile, depending on the validated test method. Sterile products are recommended for lot release testing.

Liquid or powder materials should be shipped in sterile containers that are free of detectable endotoxin. Containers for liquids should be leak-proof and sealed with Parafilm®. To minimize endotoxin adsorption, avoid using polypropylene plastics. Polystyrene plastics are recommended. If samples are non-sterile, consider shipping the sample on ice with overnight delivery.



“I am very happy with the timeliness of service and response to questions when calling in or emailing the Study Directors (in specific, dealing with Quinton Inglet, who has been wonderful about answering many of my questions).  There is good flow of communication about test results.  I especially appreciate the web page ability to look up the study results either in progress or as a completed report.  Thank you!”
-       Jamie, Operations/Quality Control, Medical Device Manufacturer
MN:BARRACUDA