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PubMed1996

Comparison of 5-hydroxy-2, 3-dihydrophthalazine-1, 4-dione and luminol as co-substrates for detection of horseradish peroxidase in enhanced chemiluminescent reactions.

The utility of 5-hydroxy-2, 3-dihydrophthalazine-1, 4-dione (HDP) as a co-substrate for the chemiluminescent detection of horseradish peroxidase was assessed. Several substituted aryl boronic acid derivatives (4-phenyl, 4-iodo) acted as potent enhancers of the peroxidase catalyzed reaction. Addition of chelating agents (EDTA) and surfactants (Tween-20 and [poly (vinylbenzyl)tributylphosphonium chloride-poly (vinylbenzyl) trioctylphosphonium chloride copolymer]) modulated background light emission and the intensity and duration of the signal from both HDP and luminol. However, HDP was found to be inferior to luminol in the peroxidase assay. Comparative studies revealed that at 500 amol of peroxidase the S/B was ten-fold higher using a commercial luminol-based signal reagent as compared with an HDP-EDTA-Tween-20 reagent (S/B t = 0 min 21.8 vs 1.7, S/B t = 10 min 17.8 vs 2.0).

Boronic Acids↗
PubMed2001

Menadione-catalyzed luminol chemiluminescent assay for the viability of Escherichia coli ATCC 25922.

Escherichia coli ATCC 25922 produced O2- in the presence of menadione, and O2- -dependent luminol chemiluminescence intensity was proportional to colony-forming unit (CFU) in the exponential phase. CFU was determined by using a 96-well plate at a range of 3 X 10(3) to 8 x 10(7) CFU /well (0.1 ml) after a 10-min incubation with menadione, followed by chemiluminescent assay for 5 s. After a 4-hr incubation of E. coli (10(5) CFU/0.1 ml) with menadione and an antimicrobial agent inhibiting the synthesis of peptidoglycan, protein, and DNA, the inhibitory concentration (IC) of the antimicrobial agent determined by menadione-catalyzed luminol chemiluminescent assay was in good agreement with minimal inhibitory concentration (MIC) of the NCCLS (National Committee for Clinical Laboratory Standard) method requiring 18 hr. Menadione-catalyzed luminol chemiluminescent assay is expected to be useful for the rapid determination of cell viability under the conditions of various cell growths and stresses.

Amikacin↗
PubMed2002

Menadione-catalyzed luminol chemiluminescent assay for viability of Mycobacterium bovis.

Stable luminol chemiluminescence was observed 10 min after the addition of menadione to a suspension of Mycobacterium bovis homogenized in Middlebrook 7H9 broth base including OADC enrichment. The chemiluminescence intensity was proportional to the absorbance of the bacterial suspension at 600 nm in a range of 0.005 to 0.15. Luminol chemiluminescence disappeared after 10 min incubation of M. bovis at over 60% of ethanol or 4 days of cultivation of M. bovis in the presence of 40 microg/ml of streptomycin. The bacterium showing the disappearance of chemiluminescence could not grow after being washed, suggesting that the inhibition concentration of the antimicrobials can be estimated on the basis of the disappearance of chemiluminescence. Menadione-catalyzed luminol chemiluminescent assay was rapid and sensitive in comparison to turbidimetry, tetrazolium (WST-8) reduction assay, and the assay using the Mycobacteria growth indicator tube (MGIT).

Catalysis↗
PubMed1995

Does luminol chemiluminescence detect free radical scavengers?

Thiol compounds have been reported to abolish hypoxanthine/xanthine oxidase induced luminol chemiluminescence and this effect has been attributed to scavenging of superoxide (O2-)/(H2O2) produced from hypoxanthine/xanthine oxidase. Yet other workers have reported that thiol compounds have shown little, if any, reactivity towards O2-/H2O2. The aim of this study was to examine the discrepancy between these two sets of findings further. Captopril (a thiol angiotensin-converting enzyme (ACE) inhibitor) and MPG (a simple thiol) were observed to abolish hypoxanthine/xanthine oxidase induced chemiluminescence. The reactivity of captopril and MPG towards O2-/H2O2 was then determined by measurement of thiol oxidation in captopril and MPG after their incubation with hypoxanthine/xanthine oxidase. Incubation (at 10 min, 37 degrees C) with 4 mM hypoxanthine/0.03 u ml-1 xanthine oxidase resulted in 7% and 20% thiol oxidation in captopril and MPG (at 1 mM) respectively. Captopril and MPG, therefore, appeared to be ineffective scavengers of oxidants produced by hypoxanthine/xanthine oxidase. Captopril and MPG also did not affect urate production or oxygen consumption by xanthine oxidase which indicated that captopril and MPG quench luminol chemiluminescence by a mechanism that excludes the inhibition of xanthine oxidase. Hypoxanthine/xanthine oxidase induced luminol chemiluminescence may, therefore, be an unsuitable method for measuring free radical scavenging activity by drugs.

Antioxidants↗
PubMed1984

Comparison between luminol- and lucigenindependent chemiluminescence of polymorphonuclear leukocytes.

Phorbolmyristate acetate (PMA) induced both a luminol- and a lucigenindependent chemiluminescence response in normal polymorphonuclear leukocytes (PMNL). PMNL isolated from a patient with a myeloperoxidase (MPO)-deficiency were found to produce almost no luminol-dependent chemiluminescence. The lucigenin-dependent chemiluminescence response was, however, found not to differ between normal and MPO-deficient cells. From these results it was concluded that the luminol- and the lucigenin-dependent chemiluminescence differed in the dependence of MPO. Results obtained with cell-free MPO-H2O2- and superoxide anion producing systems further supported this conclusion.

Acridines↗
PubMed1978

Correlation between hemin content and the chemiluminescent luminol reaction with bacteria.

Protohemin and covalently bound hemin were determined in eight aerobic bacterial strains. A good correlation between protohemin content and luminol reactivity was found. The ratio of luminol reaction to protohemin for the eight investigated strains was essentially identical to that of pure protohemin, 0.7 X 10(16) mV/mol. Covalently bound hemin contributed to the chemiluminescence to a minor extent only (0.7 X 10(14) mV/mol, in accordance with earlier observations of the lower reactivity of cytochrome c and related compounds. A difference in reaction kinetics of the luminol reaction with covalently bound hemin (slower reaction than protohemin) and protohemin was observed in vivo as well as in vitro. The phenomenon could be used to differentiate between strains with different hemin composition.

Aerobiosis↗
PubMed1980

Luminol-amplified chemiluminescence: a sensitive method for detecting the carrier state in chronic granulomatous disease.

Patients with chronic granulomatous disease have a marked defect in neutrophil oxidative metabolism and microbicidal activity. Asymptomatic mothers of males with the disease can usually be identified as heterozygous carriers by intermediate leukocyte function. Most mothers of females with the disease, however, have normal leukocyte function, and the pattern of genetic transmission in these families has been difficult to establish. Of 14 mothers of males and females with chronic granulomatous disease, 10 had been found previously to have intermediate values for neutrophil bactericidal activity, oxygen consumption, hexose monophosphate shunt activity, and Nitro Blue Tetrazolium reduction, and 4 had normal in viro leukocyte function. In the present study, 4 of these 14 mothers had normal neutrophil bactericidal activity, 3 had normal zymosan-stimulated chemiluminescence, but none had normal luminol-amplified zymosan-stimulated chemiluminescence. The presence of luminol (5-amino-2,3-dehydro-1,4-phthalazinedione) in the phagocytic mixtures markedly increased the sensitivity of the assay, permitting detection of subtle defects in leukocyte oxidative metabolism in three previously unidentifiable carriers of the disease. Thus, luminol-amplified chemiluminescence appears to be one of the most sensitive methods available for detection of chronic granulomatous disease heterozygotes; the simplicity and reproducibility of the microtechnique permit evaluation of leukocyte function in infants and newborns.

Adult↗
PubMed2003

Effect of the isocoumarin paepalantine on the luminol and lucigenin amplified chemiluminescence of rat neutrophils.

Paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naphto(2,3c)pyran-1-one), a natural isocoumarin isolated from the capitula of Paepalanthus bromelioides (Eriocaulaceae), was assessed for its effect on the respiratory burst (zymosan-stimulated luminol-enhanced chemiluminescence and PMA-stimulated lucigenin-enhanced chemiluminescence) of polymorphonuclear neutrophils in vitro. Special attention was devoted to establishing the IC(50) for neutrophils. Paepalantine was able to decrease luminol and lucigenin chemiluminescence, reflecting an inhibitory effect on the respiratory burst, with an ED(50) of 0.44+/-0.05 and 0.84+/-0.15 microg/ml, respectively. A cell-free system was performed with paepalantine on myeloperoxidase/H(2)O(2) and myeloperoxidase/H(2)O(2)/Cl(-) systems. Paepalantine inhibited luminol oxidation in both systems. This inhibition was related to the interaction of paepalantine-myeloperoxidase and its scavenger effect on HOCl.

Acridines↗
PubMed1998

[Assay for oxidative stress injury by detection of luminol-enhanced chemiluminescence in a freshly obtained blood sample: a study to follow the time course of oxidative injury].

To evaluate occurrence of oxidative stress in circulating blood, we developed standard methods to assess (1) granulocytes status as a source of reactive oxygen species (ROS) and (2) lipid peroxidation (LPO). A simplified and highly sensitive assay was developed by utilizing the chemiluminescence (CL) from luminol oxidized by ROS. 1. The CL, from 300 microliters medium containing 1% blood, 10 micrograms/ml luminol and 0.025 microgram/ml phorbol myristate acetate, well reflected the primed granulocyte status induced by in vitro contact with lipopolysaccharide (LPS). This CL was weakened slightly by superoxide dismutase and catalase, but markedly decreased by sodium azide. 2. We determined the optimal conditions for the t-butyl hydroperoxide (t-BuOOH)-stimulated CL method to evaluate plasma LPO in experiments on rat plasma added with phosphatidylethanolamine hydroperoxide (PEOOH). The CL from 300 microliters medium containing 6.67% plasma. 10 micrograms/ml luminol and 5 mumol/ml t-BuOOH was proportional to the added PEOOH amount. The integrated CL of the plasma with 0-60 nmol of PEOOH gave values of 8.280-14.213 x 10(6) counts/60 min/tube. 3. Only 100 microliters of freshly drawn blood was enough for the two CL methods to detect the generation of ROS and the occurrence of LPO. These CL methods enabled the determination of the time course of oxidative stress occurrence in circulating blood of rats treated with 5 mg/kg LPS, i.p.

Animals↗
PubMed1992

Luminol luminescence induced by 2,2'-Azo-bis(2-amidinopropane) thermolysis.

2,2'-Azo-bis(2-amidinopropane) thermolysis induces luminol luminescence. The luminescence intensity is quenched by SOD, catalase, Trolox and human blood serum. However, the time course of the light intensity profile is different for the different additives. In particular, the quenching efficiency of Trolox and human blood serum decreases with time after addition. Double quenching experiments show that SOD and Trolox are not competitive quenchers, while a simple competition can be established between Trolox and human blood serum in trapping a common intermediate. From the kinetic analysis of the data it is concluded that, at least at low additive concentrations, Trolox scavenges a luminol derived radical. Higher concentrations of Trolox or human blood serum produce induction times that are proportional to the additives concentrations. The possibility of employing luminol luminescence in the evaluation of TRAP levels and the capacity of biological samples to scavenge free radicals is discussed.

Amidines↗
PubMed2004

Menadione-catalyzed luminol chemiluminescence assay for the rapid detection of viable bacteria in foods under aerobic conditions.

A menadione-catalyzed luminol chemiluminescence assay was developed for the rapid detection and estimation of viable bacteria in foods. The principle of this assay is based on the extracellular menadione-catalyzed active oxygen spieces (O2- and H2O2) generated by the activity of NAD(P)H:menadione oxidoreductase in viable cells. This luminol chemiluminescence assay requires 10 min for the incubation of cells with menadione and then 2 s for the measurement of chemiluminescence intensity after an injection of luminol solution without the treatment of cell lysis. This method was evaluated using liquid food samples of milk, vegetable juice, green tea, and coffee spiked with Escherichia coli ATCC 25922. The study result revealed that E. coli contamination at 1 to 10 CFU/ml in these foods could be detected after incubation at 37 degrees C for 7 h in an enrichment medium; however, the green tea and coffee samples requires filtration. This method could be a useful tool for the rapid evaluation of microbial food contamination.

Colony Count, Microbial↗
PubMedDate not supplied

Quality control of reactive oxygen species measurement by luminol-dependent chemiluminescence assay.

A total of 28 donor semen samples were used to evaluate the characteristics of laboratory variability in measuring reactive oxygen species (ROS). The objectives of this study were to assess the interassay (same sample observed on different days by the same observers) variability; interdonor, intraobserver (replications of the same sample on the same day) variability; and interobserver (multiple observers on the same day with the same sample) variability of the luminol-dependent chemiluminescence assay and to establish an optimal semen age and sperm concentration. Semen samples were collected from 6 healthy donors for 108 measures of ROS. ROS levels were measured by the assay using luminol as the probe. An additional assessment measured the effect of time (age of the sample) on ROS production in 12 donor samples at 60, 120, 180, and 240 minutes after the specimen was produced. Last, to evaluate the effect of sperm concentration on ROS production, ROS levels were measured in 10 donor sample aliquots with sperm concentrations ranging from 1 to 120 x 10(6)/mL. In the controls, the mean ROS level was 0.218 x 10(6) counted photons per minute; the interassay variability standard deviation (SD) was 0.077. The interobserver SD was 0.002 for an interobserver reliability of 97.5% (coefficient of variation [CV] = 0.9%). The intraobserver (between replication) SD was 0.001 for an intraobserver reliability of 98.7% (CV = 0.5%). The interassay SD was 0.005 for an interassay reliability of 93.8% (CV = 2.0%). There was no statistically significant interobserver, intraobserver, or interassay variation (P > .80). ROS levels decreased significantly with time; a dramatic decline in ROS production was seen in the specimens that were more than 60 minutes old (P < .001). ROS values decreased by 31% at 120 minutes and 62% at 180 minutes compared with the 60-minute-old specimens. A linear relationship was seen between the ROS levels and sperm concentration in 8 of the 10 samples analyzed (R2 = .99). Our results demonstrate that the luminol-dependent chemiluminescence assay for ROS measurement is both accurate and reliable when the sperm concentration is greater than 1 x 10(5)/mL and the samples are analyzed within the first hour after specimen collection.

Clinical Laboratory Techniques↗
PubMedDate not supplied

[Interaction of human serum albumin with luminol].

Chemoluminescent and fluorescent studies of the interaction between serum albumine and luminole have been carried out. An increase of chemoluminescent intensity and quenching of luminole fluorescence dependent on protein concentration has been observed. Possibility of complex formation and the mechanism of fluorescence quenching with luminole are discussed.

Fluorescence↗
PubMedDate not supplied

[Study of oxygen photoreduction in chloroplasts by the method of luminol and chlorophyll chemiluminescence].

The reduction of oxygen by irradiated chloroplasts was studied for elucidation of oxygen action site in the electron transport chain of photosynthesis. Chemiluminescence system, consisted of luminol and peroxidase, was used for registration of oxygen reduction products. In the first case chemiluminescence system was added to supernatant fraction after centrifugation of suspension of irradiated chloroplasts in order to determine H2O2 which was found to be the final product of oxygen photoreduction. In the second case when chloroplasts were illuminated in the presence of chemiluminescence system and oxygen the fact delayed luminescence of luminol was observed. This photoluminescence related also with the oxygen reduction in chloroplasts caused a possible formation of radicals HO2 (or -O2). The formation of this radicals and H2O2 was inhibited by DCMU, heating of chloroplasts at 45 degrees C for 5 min and by washing with EDTA and NH2OH. The rate of HO2 dissappearance was increased by methylviologen. The kinetics of photoluminescence of luminol and afterglow of chlorophyll in chloroplasts was identical in the interval from 20 msec to several seconds. It is suggested that oxygen reaction site is located near the reaction centre of chloroplasts.

Chloroplasts↗
PubMed2005

[Determination of I- by the ECL of luminol in neutral medium].

Based on the studies of electrochemiluminescence(ECL) of luminol in neutral medium, the iodide would greatly sensitize the ECL of luminol. The ECL luminous intensity responded linearly to the concentration of iodide within the range of 3.8 x 10(-7) mol x L(-1) to 2.2 x 10(-6) mol x L(-1), and the detection limit is 4.0 x 10(-8) mol x L(-1). The mechanism of enhancement effect of iodide on luminol's ECL is also discussed. The experimental results showed that it was a free radical procedure.

Buffers↗
PubMed1991

[Role of active forms of oxygen in inducing luminol-dependent chemiluminescence in macrophages].

The luminol-dependent chemiluminescence of mouse peritoneal macrophages during phagocytosis of opsonized zymosan was studied by using specific active oxygen scavengers and metabolic inhibitors. Extracellular hydrogen peroxide and superoxide anion were shown to contribute immensely to the induction of the chemiluminescence. The role of the hydroxyl radical was rather insignificant, whereas singlet oxygen was not involved in this process. The interaction between luminol and peroxide was shown to be peroxidase-dependent. An inhibitory analysis revealed that the interaction between luminol, peroxide and superoxide anion obeyed a hybrid enzyme-free radical mechanism.

Animals↗
PubMed1987

Luminol- and lucigenin-dependent chemiluminescence of neutrophils: role of degranulation.

The role of myeloperoxidase in luminol- and lucigenin-dependent chemiluminescence of stimulated human neutrophils has been investigated using purified myeloperoxidase and anti-(human myeloperoxidase) antiserum. This antiserum has been used as a specific enzyme inhibitor to assess myeloperoxidase-dependent neutrophil functions in single preparations of cells, thus overcoming the limitations inherent in other approaches using non-specific haem-inhibitors or myeloperoxidase-deficient neutrophils. The results show that luminol-dependent chemiluminescence is largely dependent on both oxidase activity and degranulation (of myeloperoxidase), while lucigenin monitors oxidase activity independently of the extent of degranulation. Since oxidase activation can occur in the absence of degranulation, assays utilizing luminol-dependent chemiluminescence to measure oxidant generation by stimulated neutrophils should include saturating levels of exogenous myeloperoxidase to overcome this problem.

Acridines↗
PubMed2005

Effect of model ligands on iron redox speciation in natural waters using flow injection with luminol chemiluminescence detection.

The effects of dissolved organic compounds on the determination of nanomolar concentrations of Fe(II) have been compared using two luminol-based flow injection chemiluminescence (FI-CL) methods. One used the direct injection of sample into the luminol reagent stream, and the other incorporated on-line solid-phase extraction of the analyte on an 8-hydroxyquinoline microcolumn. The CL signals from analyses of dissolved iron species (Fe(II) and Fe(III)) with model ligands and organic compounds were examined in high-purity water and seawater. The organic compounds included natural reducing agents (e.g., ascorbic acid), nitrogen sigma-donor/pi-acceptor compounds (e.g., 1,4-dipyridine, protoporphyrin IX), aromatic compounds (e.g., 1,4-dihydroxybenzene), synthetic iron chelators (e.g., EDTA), and natural iron binding compounds (e.g., desferrioxamine B, ferrichrome A). Fe(II) determinations for both luminol FI-CL methods were affected by submicromolar concentrations of redox-active compounds, strong iron binding ligands (i.e., log K(FeL) > 6), and compounds with electron-donating functional groups in both high-purity water and seawater. This was due to reactions between organic molecules and iron species before and during analysis, rather than chemiluminescence caused by the individual organic compounds. In addition, the effects of strong ligands and size speciation on Fe(II) recoveries from seawater following acidification (pH 2) and reduction (100 microM sodium sulfite) were investigated.

Journal Article↗