Gibraltar Labs Inc. is an ISO 17025 certified testing laboratory to perform Limulus Amebocyte Lysate (LAL) Test.  LAL, also known as Bacterial Endotoxin test, is a highly sensitive test used to detect or quantify bacterial endotoxins. Bacterial endotoxins, also known as pyrogens, are fever causing byproducts of gram negative bacteria. It is performed as an end-product endotoxin test for human and animal injectable drugs, biological products, and medical devices.

History: Rabbit pyrogen test was the first test used to detect endotoxins. LAL test officially replaced the rabbit pyrogen test due to its greater sensitivity because in rabbit pyrogen test, endotoxin amount wasn’t quantifiable. Amebocyte lysate from the horseshoe crab (Limulus poylphemus) was discovered to be the agent responsible for the blood clot in the amebocytes of the crab when came in contact with endotoxins. Amebocyte extract is now commercially prepared to be used as the major reagent used to detect and measure endotoxins. LAL test is a valuable test because it prevents the administration and or use of products and drugs which may cause fever, shock and death if highly endotoxic.

There are two methods of LAL endotoxin testing performed daily by Gibraltar’s highly experienced technicians. Gel-Clot method is based on the formation of clotting of the lysate in the presence of bacterial endotoxins in the test material. Kinetic Chromogenic method utilizes a microplate reader to automatically detect the amount of endotoxin concentration present in the sample when tested against a known amount of standards. Sensitivity of each test is based on the manufacturer’s label claim of the Lysate. Each new lot of reagents, a confirmation of label claim is performed by our certified technicians before a test can be considered valid and be performed on a routine basis. Gel-Clot has 0.03 EU/mL labeled lysate sensitivity and Kinetic Chromogenic has a sensitivity of 0.005 EU/mL.

Analyst qualification: Each one of our technicians who are certified to perform endotoxin testing also perform a proficiency test yearly to show competence in LAL Gel-Clot and/or Kinetic Chormogenic Test.

There are many other  qualifications, calibrations and proficiencies that we routinely perform and document so as to be certified to offer this critical service to you our customers.

All methods used in Gibraltar Laboratories follow Current USP <85> and <161>, EP, JP, ANSI/AAMI ST72 and FDA guidelines and are performed based on Standard Operating Procedures under GMP/GLP environment.

Any questions and/or concerns about the LAL bacterial endotoxin test, Gibraltar’s team of LAL experts will be happy to assist you.

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  1. Good day sir/madam!

    I have read the article that you have posted on your website regarding on Endotoxin Testing Methods, the Gel -Clot Method and Kinetic Chromogenic Method, and as a high school student I found it very interesting and helpful. As part of our school curriculum, we are obliged to submit an investigatory project. My investigatory project was titled as Pathogen Detection property of Limulus amoebocyte lysate (LAL)from Cacinoscorpius rotundicauda (Mangrove Horseshoe Crab) against lipopolysaccharide and other endotoxins. As part of my research study, I would like to seek an expert’s advice on how can I make my investigatory project successful. There are a few questions that I would like to ask you:
    1. Which is better to use, a commercially available Freeze-Dried LAL sample or a fresh LAL sample directly gathered from the Mangrove Horseshoe Crab?
    2. Using the Gel-Clot Method, how would I be able to know the quantity of Endotoxins present in the sample I have. Is there any guide or table that I could use to identify the amount of Endotoxins present?

    Your immediate response will be highly appreciated.
    Thank you.

    • Hello

      I would use the Gel clot test at your level. I would use a commercially licensed vendor of LAL like Associates of Cape cod or Endosafe. You can quantify the response in terms of Endotoxin units per gram or ml.

      Good Luck!

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