Endotoxin assay

Bergen Community College Introduction Contamination by Gram-negative bacteria is one of the major reasons for sterile products recalls in the United States [1]. Endotoxins are major structural components in the cell wall of Gram-negative bacteria [2].

Endotoxin assay

Turbidimetric Endotoxin Test Bacterial endotoxin test by gel clot method Accugen laboratories utilize the LAL endotoxin test Limulus Amebocyte Lysate Gel Clot method to test raw materials or end products for the presence of endotoxins. This method uses components found in the blood of the Blue Horseshoe Crab, Limulus polyphemus, which forms a gel-like clot when incubated in the presence of endotoxins.

This method is used to determine if products or materials are "endotoxin free". The sensitivity or detection limit of the endotoxin test is 0.

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Products and materials can be certified to a sensitivity of 0. Upon receiving the product to be tested at Accugen Laboratories, a product extract is made and then exposed to and incubated with the horseshoe crab lysate LAL. The product extract is incubated along with a standard series of the Control Standard Endotoxin CSE as the positive control and the unexposed extract fluid as a negative control.

After the incubation period, Endotoxin assay tubes containing the controls and the extract are observed for the presence of the gel clot. If it clots, endotoxin is present.


If no clot is observed, the product is free of endotoxin. When using the LAL Endotoxin Gel Clot method, there are two separate types of tests that can be performed on a particular product, a qualtitative or a quantitative assay.

Endotoxin assay

The quantitative LAL assay endotoxin testing is usually used on liquid products in which a Preliminary Assay and a Validation of a dilution series is performed. Although not common, the quantitative assay can be performed on devices.

The Preliminary Assay endotoxin tests the pH of the product. The pH must be compatible with the LAL gel clot assay in order for a validation to be performed.

Qualitative endotoxin testing also utilizes the LAL Endotoxin Gel Clot method but rather than trying to detect the quantitative level of endotoxins, it tests the endotoxin levels of the product to be either greater than or less than the sensitivity of the test, which is 0. This type of test can be performed on solid and liquid products.

Kinetic Turbidimetric

Bacterial endotoxin test by Chrmogenic LAL Endotoxin Test Method The kinetic chromogenic endotoxin test is a reaction between bacterial endotoxin present in a test material and synthetic chromogenic LAL reagents. Color changes if endotoxin is present in the test material.

Test sensitivity depends upon the specific lysate used. Lowest detection limit in case of kinetic chromogenic test is 0. If endotoxin is present, clotting of the solution results in cloudiness which reduces the transmittance of light when observed under spectrophotometer.

Lowest detection limit in case of turbidimeteric endotoxin test is 0. For liquid samples, a minimum of 5 ml is required and powder samples require enough material to reconstitute into a minimum of 5 ml pyrogen-free water.

Initial validation on 3 lots must be performed in order to validate the method of testing for a given product. Frederick Bang in the early 's discovered that the horseshoe crab's blood cells, called amoebocytes, contain a clotting agent that attaches to dangerous endotoxins produced by gram negative bacteria.

Endotoxin is an essential lipopolysacchride LPS component of the cell wall of Gram-negative bacteria which elicits a pyrogenic response when injected into the human bloodstream. They are also toxic to cells grown in tissue culture conditions.

When the bacterial cell dies, the membrane of the cell ruptures and endotoxins are released into the surrounding environment.May 18,  · The Endotoxin Activity Assay (EAA™; Spectral Diagnostics Inc., Toronto, ON, Canada) is a rapid in vitro diagnostic test that is based on the reaction of neutrophils to endotoxin complexed with an anti-endotoxin antibody and that allows measurement of endotoxin activity levels in whole blood at the bedside [1 – 3].

A Limulus amoebocyte lysate (LAL) assay can take as little as 45 minutes. A suspect sample is mixed with reconstituted LAL and allowed to sit in a small tube. A suspect sample is mixed with reconstituted LAL and allowed to sit in a small tube. Horseshoe Crabs and Endotoxin Testing.

From the s through the late s, rabbits were used to screen products such as pharmaceuticals for the presence of pyrogenic substances like endotoxin. Request price quotes of the PYROSTAR™ Limulus Amebocyte Lysate Test or ES-F LAL assay.

(LAL) reagent product line, our trademark PYROSTAR offers accessories, kits and solutions for use in the different endotoxin detection assays.

View Gel Clot Reaction Tubes, Lysate Reagent Water, Toxinometer® ET Series and more. To accurately measure endotoxin levels in a sample, the LAL assay uses an endotoxin standard of known concentration that is derived from E. coli strain OB4. This standard is provided with each kit and is used to create a standard curve.

Usefulness of the endotoxin activity assay to evaluate the degree of lung injury Yuichiro Sakamoto* this problem, a diagnostic kit called the Endotoxin Activity Assay (EAATM, Spectral Medical Inc., Toronto, Canada) was developed.

In the EAATM, a monoclonal antibody against.

LAL Reagent Test Kit, Limulus Amebocyte Lysate |PYROSTAR™