• YAKHAK HOEJI
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• v.43 no.5
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• pp.606-613
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• 1999

To survey the possibility of replacing the pyrogen test with Limulus Amebocyte Lysate(LAL) test and to find out a standard methods suitable to our blood products made in Korea, 100 samples of 20% human serum albumin were tested by commercial LAL test kits and results of those were compared with rabbit pyrogen test. The LAL test is used both dinetic-chromogenically and kinetic-turbidimetrically. Both methods equally showed broad detection range (5.0~0.005 EU/ml), excellent sensitivity ($\geq$ 0.005 EU/ml) and predominant recovery rate within valid dilution range, but kinetic-turbidimetric method seemed to be more reproducible than kinetic-chromogenic method(kinetic-chromogenic method : S.D. = 15.88, kinetic-turbidimetric method : S.D. = 8.12). After heating the sample at 75$^{\circ}C$ for 15 min, the results showed a little elevated recovery rate with both methods. After performing the test on 100 albumin samples with both kits, the results were analysed using the USP standard (1.33 EU/ml). 7% of samples in kinetic-chromogenic methods and 1% of samples in kinetic-turbidimetric method exceeded the limit of endotoxin levels regulated for blood products in USA. Because this phenomenon was not observed in both methods at the same time and both methods have high sensitivity ($\geq$0.005 EU/ml), these results seemed to depend on nonspecific reaction. Considering its sensitivity and reproducibility, we could assure that LAL test is proper to detecting pyrogenic with good sensitivity.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.171-180
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• 2024

The endotoxin test is based on the reaction between Limulus Amebocyte Lysate (LAL) and the lipopolysaccharides of Gram-negative bacteria. In this study, we sought to identify factors that interfere with the LAL testing of radiopharmaceuticals and evaluated acceptable ranges. A gel-clot LAL test and a chromogenic LAL test were used as endotoxin tests. We compared the performances of the Endosafe^Ⓡ LAL and recombinant Endosafe^Ⓡ Recombinant Cascade Reagent (rCR) cartridges for the chromogenic test. The factors that interfered with ⁶⁸Ga-DOTATOC injection were pH, 4-(2-hydroxyethyl) piperazine-1-ethanesulfonic acid (HEPES) buffer, and organic solvents, especially ethanol. However, interference by these factors was overcome by diluting the ⁶⁸Ga-DOTATOC injection tenfold. In addition, no interference was observed at pH values between 4 and 8, at a HEPES concentration of 2,000 ㎍/mL, or an ethanol concentration of <1%. Furthermore, results showed that interfering factors had similar effects on the performances of the Endosafe^Ⓡ LAL and Endosafe^Ⓡ rCR cartridges. The results of this study are expected to be useful for evaluating factors that interfere with the endotoxin testing of new radiopharmaceuticals.

• Journal of Life Science
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• v.11 no.1
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• pp.27-29
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• 2001

Vibrio vulnificus endotoxin was extracted, analyzed the chemical composition, tested its biological activity, and compared to those of Escherichia coli and Salmonella typhimurium. The major fatty acid of three endotoxins were different each other; V. vulnificus endotoxins were different each other; V. vulnificus endotoxin was myristric acid (C14:0), E. coli was lauric acid (C12:0), S. typhimurium was capric acid (C10:0). The biological activities of V. vulnificus endotoxin were similar to those of E. coli and S. typhimurium in terms of the gelation activity of the Limulus amebocyte lysate and the lethal toxicity. But the result of enzyme (AST, ALT, and LDH) analysis showed that the enzyme activity of V. vulnificus endotoxin was similar to that of E. coli, but smaller than that of S. typimurium.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.132-135
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• 2003

Endotoxin concentrations were measured from 69 point-of-use(POU) water treatment system(WTS) by using Limulus amebocyte lysate(LAL) assay, and the results were compared to heterotrophic bacterial data. Endotoxin concentrations in all POU WTS water samples and tap waters varied within the range 0.8-79.1EU mL$\^$-1/ and 0.1-3.4EU mL$\^$-1/, respectively, The correlations between endotoxin concentration and HPC bacteria from the water samples showed not significant(r=0.18).

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.85-88
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• 1986

To estimate the effect of some injectable antibiotics (ampicillin sodium, cefazolin sodium, cephaloridine, cefuroxime sodium and chloramphenicol sodium succinate) on pyrogen tests, the Limulus amebocyte lysate (LAL) test and an ultrafiltration technique were used. The rabbit pyrogen test was also used in the case of cafazolin sodium. At high antibiotic concentrations, these samples which were artificially contaminated with endotoxin inhibited the gelation reaction of LAL. But the gelation reaction occurred when most of the antibiotic was removed by ultrafiltration. Likewise, cefazolin sodium interfered not only with the LAL test but also with the rabbit pyrogen test. From these results it can be said that special modification to eliminate interference should be taken into consideration for valid method of pyrogen tests in the parenteral products containing these antibiotics.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.109-112
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• 2020

To evaluate the safety of bacteriophages for application of sanitizer, endotoxin content and cell cytotoxicity of two Escherichia coli and four Staphylococcus aureus phages were determined. Endotoxin ratio was determined by the Limulus amebocyte lysate (LAL) assay as a test for representative biological endotoxin content. The average endotoxin average content of the 9 log PFU/mL lysate was 18.6 EU/mL and that of the 10 log PFU/mL lysate was 5.9 EU/mL, suggesting that the phage lysate was not suitable for clinical applications, but suitable for food pathogen control applications. To confirm the cell cytotoxicity of the phage lysates, MTT assay was performed using Raw 264.7 cells treated with 9 log PFU/mL phages. Results of the assay indicated that the phage lysates did not significantly decrease the cell viability (p>0.05). These results indicated that bacteriophages would be suitable as a food safety sanitizer.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.124-129
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• 2016

Endotoxin, also known as lipopolysaccharide (LPS) produced by the cell wall of gram negative bacteria can be present in any liquid or on any biomaterial. Endotoxin in blood can cause fever and inflammation. In this study, we compared bacterial endotoxin using Escherichia coli O157:H7, Klebsiella oxytoca, Salmonella Typhi, Shigella sonnei and Morganella morganii. Bacteria were cultured for use in the experiment, and diluted to $1.5{\times}10^8CFU/mL$. A check marked sensitivity confirmatory test of the Limulus amebocyte lysate (LAL) reagent was performed to examine the validity. The end point reaction to each bacteria sample was confirmed with 10 fold dilution and then the final reaction end point was confirmed by 2 fold dilution between the dilution step and the upper dilution step. According to the results, in detection of endotoxins in more than 0.015 EU/mL, E. coli O157 was 75~37.5 CFU/mL, K. oxytoca 37.5~18.75 CFU/mL, M. morganii and S. Typhi 3.75~1.875 CFU/mL, and S. sonnei 7.5~3.75 CFU/mL. The resulting value was finally ensured by a confirmation test for the inhibitory factor. Based on this study, conduct of further research on bacterial endotoxin is encouraged.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.132-136
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• 2004

The LAL (Limulus amebocyte lysate) test for the detection and quantification of endotoxin is based on the gelation reaction between endotoxin and LAL from a blood extract of Limulus polyphemus. The test is labor intensive, requiring dedicated personnel, a relatively long reaction time (approximately 1 h), relatively large volumes of samples and reagents and the detection of the end-point is rather subjective. To solve these problems, a miniaturized LOC (lab-on-a-chip) prototype, 62mm (L) ${\times}$ 18 mm (W), was fabricated using PDMS (polydimethylsiloxane) bonded to glass. Using this prototype, in which 2mm (W) ${\times}$ 44.3mm (L) ${\times}$ 100 $\mu\textrm{m}$ (D) microfluidic channel was constructed, turbidometric and chromogenic assay detection methods were compared, and the chromogenic method was found the most suitable for a small volume assay. In this assay, the kinetic-point method was more accurate than the end-point method. The PDMS chip thickness was found to be minimized to around 2 mm to allow sufficient light transmittance, which necessitated the use of a glass slide bonding for chip rigidity. Due to this miniaturization, the test time was reduced from 1 h to less than 10 min, and the sample volume could be reduced from 100 to ca. 4.4 ${\mu}$L. In summation, this study suggested that the LOC using the LAL test principle could be an alternative as a semi-automated and reliable method for the detection of endotoxin.

• KSBB Journal
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• v.18 no.5
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• pp.429-433
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• 2003

LAL (Limulus amebocyte lysate) test to detect and quantity endotoxin is based on gellation reaction between endotoxin and LAL from a blood extract of Limulus polyphemus. The test is labor intensive requiring dedicated personnel, takes relatively long reaction time (approximately 1 hr), requires relatively large volume of samples and reagents, and its end-point detection method is rather subjective. To solve these problems, we attempted to develop a miniaturized LOC (lab-on-a-chip) prototype using PDMS and glass. Using the 62 mm (length) ${\times}$ 18 mm (width) prototype in which 2 mm (width) ${\times}$ 44.34 mm (length) ${\times}$ 100 $\mu\textrm{m}$ (depth) microfluidic channel was provided, we compared the various detection methods of gellation, turbidometric, and chromogenic assays to find the chromogenic method to be the most suitable for small volume assay. In this assay, kinetic point method was more accurate than end point method. We also found the PDMS chip thickness should be minimized to around 2 mm to allow sufficient light transmittance, which necessitated a glass slide bonding for chip rigidity. Through the miniaturization, the test time was reduced from 1 hr to less than 10 minutes, and the sample volume could be reduced from 100 ${\mu}\ell$ to 4.4 ${\mu}\ell$. In sum, this study revealed that the mini LOC could be an alternative for a semi-automated and reliable method for LAL test.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.405-415
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• 2014

Objectives: The aim of this study is to comprehensively summarize endotoxin levels reported in operations using metalworking fluids(MWFs). Methods: An extensive literature review was conducted of studies reporting endotoxin levels in processes using metalworking fluids. Keyword search terms included 'metalworking fluids', 'machining fluids', 'metalworking operation', 'machining operation' and 'endotoxin', which were used in combination. Results: A total of ten manuscripts were found to report on airborne endotoxin levels from metalworking operations in the automobile industry. Polycarbonate(PC), polyvinyl chloride(PVC) and mixed cellulose ester(MCE) were used to collect airborne endotoxin. Limulus Amebocyte Lysate was mainly used to quantify endotoxin amount. The levels of airborne endotoxin reviewed varied considerably, ranging from < $4EU/m^3$ to $790EU/m^3$, which was found to be far lower than those from cotton and potato processing plants, sawmills, and poultry farms. Several studies assumed that exposure to endotoxin could be a causative agent of respiratory diseases. Conclusions: Inhalation endotoxin exposure levels reported from metalworking operations were found to be lower than those from industries handling organic materials, even though it could be considered as a possible cause for several respiratory diseases.