Determination Of Acid Phosphatase Research Articles

A colorimetric platform using highly active Prussian blue composite nanocubes for the rapid determination of ascorbic acid and acid phosphatase.

Cobalt-doped Prussian blue composite nanocubes (Co-PB NCs) were synthesized, which can quickly convert O2 to O2•- and 1O2. Due to the presence of cobalt and iron transition metal redox electron pairs, Co-PB NCs with high oxidase mimetic activity can rapidly oxidize the substrate 3,3',5,5'-tetramethylbenzidine (TMB) to produce blue products (ox-TMB) without the assistance of unstable H2O2. Using ascorbic acid-2-phosphate trisodium salt (AAP) as a substrate, it can be converted to reduced ascorbic acid (AA) under acid phosphatase (ACP) hydrolysis, resulting in suppression of TMB oxidation. Therefore, an enzyme cascade signal amplification strategy for rapid colorimetric detection of AA/ACP was developed based on the high-efficiency oxidase-like activity of Co-PB NCs combined with the hydrolysis effect of ACP. The color changes at low concentrations of AA and ACP could be observed by the naked eye, and the detection limits of AA and ACP were 1.67μM and 0.0266 U/L, respectively. The developed colorimetric method was applied to the determination of AA in beverages and ACP in human serum, and the RSDs were less than 3%, showing good reproducibility. This work provides a promising strategy for the use of metal-doped Prussian blue composite material for the construction of rapid colorimetric sensing platforms that avoid the use of unstable hydrogen peroxide.

Oxidase-like Fe–N/C single atom nanozyme enables sensitive detection of ascorbic acid and acid phosphatase

The development of cost-effective and easy-to-use strategies for the detection of ascorbic acid (AA) and acid phosphatase (ACP) is in high demand but challenging. Thus, we report a novel colorimetric platform based on Fe–N/C single atom nanozyme with efficient oxidase mimicking activity for their highly sensitive detection. The designed Fe–N/C single atom nanozyme can directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to produce a blue oxidation product (oxTMB) in the absence of H2O2. In addition, L-ascorbic acid 2-phosphate can be hydrolyzed to ascorbic acid in the presence of ACP, which inhibits the oxidation reaction and results in a significant bleaching of the blue color. Based on these phenomena, a novel colorimetric assay with high catalytic activity was developed for the determination of ascorbic acid and acid phosphatase with detection limits of 0.092 μM and 0.048 U/L, respectively. Notably, this strategy was successfully applied to the determination of ACP in human serum samples and evaluate ACP inhibitors, indicating its potential as a valuable tool for clinical diagnosis and research.

MXene-derived Ti3C2 quantum dots-based ratiometric fluorescence probe for ascorbic acid and acid phosphatase determination

As a burgeoning zero-dimensional nanomaterial, MXene quantum dots which are derived from two-dimensional transition-metal carbides have attracted a lot of interest lately. The transformation of two-dimensional MXene into zero-dimensional structures of a few nanometers enables these recently discovered materials to possess an exceptional quantum size effect and remarkable photoluminescence characteristics. Hence, we synthesized N doped Ti3C2 MXene quantum dots (N-Ti3C2 MQDs) exhibiting bright blue fluorescence through small-molecule amine-assisted solvothermal strategy. In this work, we constructed a novel ratiometric fluorescence biosensor for the determination of ascorbic acid (AA) and acid phosphatase (ACP) based on the excellent optical performance of N-Ti3C2 MQDs and combined o-phenylenediamine (OPD). This ratiometric strategy was established based on the inner filter effect between N-Ti3C2 MQDs and the oxide of OPD. Sensitive fluorometric analyses of AA and ACP were achieved successfully in the respective ranges of 2–240 μM and 0.15–3.75 U/L with respective limits of detection down to 0.82 μM and 0.02 U/L. Moreover, the response time of this fluorescence sensor for AA and ACP determination was less than 1.5 h. The intraday and interday relative standard deviations for AA and ACP assay were all below 8.3 %, suggesting the good reproducibility of this sensor. In addition, the profuse color changed under UV light with analytes concentrations increased and exhibited great potential for visual detection and on-site application. The proposed method was further utilized to screen of potential ACP inhibitors, indicating that this probe has great potential in clinical practice.

PHYTOCHEMICAL SCREENING, TOXICITY EVALUATION OF POLYCARPAEA CORYMBOSA LAMK AND ITS EFFECT ON CANCER BIOMARKERS OF EHRLICH ASCITES CARCINOMA-INDUCED MICE COMPARED WITH THE REFERENCE STANDARD DRUG 5- FLUOROURACIL

Objective: The current investigation focuses on the study of efficacy of whole plant of Polycarpaea corymbosa Lamk in Ehrlich ascites carcinoma (EAC) inoculated Swiss albino mice. Methods: The whole plant of P. corymbosa Lamk (WPC) was extracted with solvents of increasing polarity and their percentage yields were calculated. The major phytoconstituents present in the plant extracts were determined by standard chemical tests. Tumor was induced in mice by intraperitoneal injection of EAC cells (1×106 cells/mouse). The in vivo antitumor effect of extracts was assessed by monitoring the mean survival time, tumor volume, effect on hematological parameters, determination of lysosome specific cancer markers (cathepsin-D), β-D glucuronidase and acid phosphatase, liver marker enzymes (5’-nuclotidase and lactate dehydrogenase), membrane bound ATPase (Na+/K+ ATPase and Mg2+ ATPase), DNA, and RNA content. Results: The percentage yield obtained were 9.87%w/w, 7.88%w/w, and 16.56% w/w for petroleum ether, ethyl acetate, and ethanol extract, respectively. The phytochemical screenings of those extracts were performed. The order of activity of extracts was ethanol extract > ethyl acetate > petroleum ether. Among the extracts, Ethanol extract of P. corymbosa Lamk. showed a significant increase in life span and decrease in viable cancer cell number and tumor volume. The protective effect of the extract on the hemopoietic system at the dose 200mg∕kg was noted. The alterations in the hematological profile, lysosome-specific cancer markers, liver-specific cancer markers, and membrane-bound ATPases DNA and RNA were restored. Conclusion: The ethanolic extract of P. corymbosa Lamk. possesses in vivo anticancer activity when compared to the tumor control group.

POSSIBILITIES OF SEMEN STAIN IDENTIFICATION AFTER CLOTHING AND BEDDING WASHING IN INVESTIGATING CASES OF SEXUAL ASSAULT

Identifying semen stains on clothing and bedding is a crucial component in investigating cases of sexual assault. In some cases, clothing and bedding have already been washed before they were removed and sent for forensic examination. There is insufficient data on best practices for handling traces of semen on clothes after washing. This work aimed to study the possibility of identifying traces of semen on clothes after washing using widely used techniques. To simulate typical physical evidence, donor semen samples were applied to pieces of clothing made from various fabrics. The clothes were washed under multiple conditions (with the help of nonbiological and biological (enzyme-containing) agents, and across numerous washing machines). After washing, the washing stains were characterized by the presence of fluorescence signal, spermatozoa (Koren – Stokis method), the determination of acid phosphatase, prostate-specific antigen and semenogelin, as well as the results of serological research according to the AB0 system and DNA analysis. Clothing analysis using these methods was shown to be effective in experimental conditions. However, the presence of enzymes as detergent components designed to destroy biogenic stains significantly affect the results of the identification of semen stains. It has been established that the full genetic profile can be obtained from semen stains even after washing three times. Different strategies are needed to detect, select and identify semen stains depending on the circumstances of a case. It is recommended to examine clothing and bedding, even if the specimens were previously washed.

Combination Therapy of Wuweizi (Schisandrae Chinensis Fructus) and Dexamethasone Alleviated Dexamethasone-Induced Glucocorticoid Osteoporosis in Rats with Idiopathic Pulmonary Fibrosis.

Objective To investigate the therapeutic effect of combined application of Wuweizi (Schisandrae Chinensis Fructus) and dexamethasone in rats with idiopathic pulmonary fibrosis (IPF) and the possible protective effect of Wuweizi against dexamethasone-induced glucocorticoid osteoporosis (GIOP). Methods There were five groups in this study, including the sham operation group, model group, Wuweizi group, dexamethasone group, and the combination group. A rat IPF model was made by the endotracheal injection of bleomycin. After modeling, rats were given drug interventions for 7 and 28 days. Rats were sacrificed for pathological morphology examination of the bone and lung and quantitative determination of biochemical markers of bone metabolism and angiogenesis-related cytokine to observe therapeutic efficacy on the 7th and 28th day. ELISA was used for the quantitative determination of tartrate-resistant acid phosphatase (TRACP), bone alkaline phosphatase (BALP), hypoxia-inducible factor (HIF-1α), platelet-derived growth factor (PDGF), pigment epithelium-derived factor (PEDF), and endostatin in serum. The concentrations of calcium (Ca) and phosphorus (P) were detected with the automatic biochemical analyzer. Results After drug interventions for 7 and 28 days, alveolitis and pulmonary fibrosis in treatment groups showed significant improvement compared with those in the model group (P < 0.05). Bone histopathological figures showed severely damaged trabecular bone and bone marrow cavity in the dexamethasone group, but it was significantly alleviated in the combination group. The concentrations of BALP and Ca in the combination group were significantly higher than those in the dexamethasone group after treatment, while the concentrations of TRACP and P were lower than those in the dexamethasone group (P < 0.05). Bone histopathological figures showed severely damaged trabecular bone and bone marrow cavity in the dexamethasone group, but it was significantly alleviated in the combination group. The concentrations of BALP and Ca in the combination group were significantly higher than those in the dexamethasone group after treatment, while the concentrations of TRACP and P were lower than those in the dexamethasone group (α), platelet-derived growth factor (PDGF), pigment epithelium-derived factor (PEDF), and endostatin in serum. The concentrations of calcium (Ca) and phosphorus (P) were detected with the automatic biochemical analyzer. P < 0.05). Bone histopathological figures showed severely damaged trabecular bone and bone marrow cavity in the dexamethasone group, but it was significantly alleviated in the combination group. The concentrations of BALP and Ca in the combination group were significantly higher than those in the dexamethasone group after treatment, while the concentrations of TRACP and P were lower than those in the dexamethasone group (P < 0.05). Bone histopathological figures showed severely damaged trabecular bone and bone marrow cavity in the dexamethasone group, but it was significantly alleviated in the combination group. The concentrations of BALP and Ca in the combination group were significantly higher than those in the dexamethasone group after treatment, while the concentrations of TRACP and P were lower than those in the dexamethasone group (α), platelet-derived growth factor (PDGF), pigment epithelium-derived factor (PEDF), and endostatin in serum. The concentrations of calcium (Ca) and phosphorus (P) were detected with the automatic biochemical analyzer. Conclusions The combination therapy of Wuweizi and dexamethasone effectively treated IPF rats by regulating angiogenesis, meanwhile distinctly alleviating dexamethasone-induced GIOP.

Photoelectrochemical determination for acid phosphatase activity based on an electron inhibition strategy

In the present work, inspired by the excellent photoelectrochemical (PEC) properties of TiO2 and g-C3N4, a simple and sensitive TNA/g-C3N4/DAT sensor for determination of acid phosphatase (ACP) was constructed based on the electron inhibition performance of 3,5-diamino-1,2,4-triazole (DAT) and coordination of Fe(II) with DAT. DAT was oxidized by sodium nitrite to its diazonium salt and then was electrochemically grafted onto the surface of TNA/g-C3N4 to form the TNA/g-C3N4/DAT, which significantly hindered the electron transfer of TNA/g-C3N4, and reduced the photocurrent response of TNA/g-C3N4 under visible light irradiation. After immersion the TNA/g-C3N4/DAT in the mixing solution containing Fe(III), AAP and ACP enzyme, the photocurrent of the TNA/g-C3N4/DAT sensor increased due to the dephosphorylation of AAP to AA catalyzed by ACP enzyme, the reduction of Fe(III) to Fe(II) by AA, and the coordination reaction of Fe(II) with DAT, the increase value of photocurrent was linear with the concentration of ACP under the optimal experimental conditions. Therefore, the constructed TNA/g-C3N4/DAT PEC sensor exhibited a satisfying linear range (0.05–100 U L−1), low limit of detection (0.016 U L−1) and good selectivity towards ACP determination, which has been successfully applied for the analysis of real human serum samples with good precision of RSD less than 4.2 % and good accuracy of the recoveries ranged from 97 % to 104 %.

Nitrogen-doped carbon dots as a ratiometric fluorescent probe for determination of the activity of acid phosphatase, for inhibitor screening, and for intracellular imaging.

The author describe a method for preparation of green fluorescent nitrogen-doped carbon dots (N-CDs) through hydrothermal treatment of a mixture of lotus leaf juice and ethylenediamine (EDA). The N-CDs have uniform size, good dispersibility and water solubility. Under 316 and 366nm photoexcitation, they show dual fluorescence with emission peaks at 415 and 509nm, respectively. They are positively charge and display low cytotoxicity. This makes them an excellent choice for fluorometric assays and for bioimaging. A ratiometric assay was developed for the determination of the activity of acid phosphatase (ACP). It is based on the aggregation- induced quenching (AIQ) of the fluorescence of the N-CDs by sodium hexametaphosphate (NaPO3)6. Enzymatic hydrolysis of (NaPO3)6 by ACP leads to the disintegration of (NaPO3)6 and to the restoration of fluorescence. The measurement of the ratio of fluorescence at two wavelengths (415 and 509nm), background interference and fluctuating signals can be widely eliminated. The method works in the 1-50U·L-1 ACP activity range and has a detection limit of 0.43U·L-1. It was successfully applied (a) to the determination of ACP in spiked serum samples, (b) to ACP inhibitor screening, and (c) to imaging of ACP in HePG2 cells. Graphical abstract Schematic presentation of the synthesis of nitrogen-doped carbon dots (N-CDs), and their application to the ratiometric fluorometric determination of acid phosphatase (ACP) based on the aggregation-induced quenching and enzymatic hydrolysis.

Colorimetric determination of ascorbic acid and the activity of alkaline phosphatase based on the inhibition of the peroxidase-like activity of citric acid-capped Prussian Blue nanocubes.

Colorimetric methods are described for the determination of ascorbic acid (AA) and alkaline phosphatase (ALP). Both assays are based on the inhibition of the peroxidase (POx)-like activity of Prussian Blue nanocubes (PB NCs) capped with citric acid. They catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by H2O2 to produce a blue color with an absorption maximum at 652nm. On addition of AA, the PB NCs are reduced to Prussian White (PW) which does not act as a POx mimic. This results in a decreased rate of the formation of the blue coloration whose intensity decreases with increasing concentration of AA. The assay allows AA to be quantified with a 35nM detection limit (at 3σ/m). The hydrolysis of AA phosphate by ALP leads to the formation of AA which can be quantified by the above method. Based on this, the activity of ALP can be determined by measurement of the intensity of the blue coloration thus formed. The method can be used to determine the activity of ALP with a detection limit as low as 0.23U·L-1. Graphical abstract Schematic presentation of a method forcolorimetric determination of ALP activity. AA obtained by ALP-catalyzed hydrolysis of ascorbic acid phosphate (AAP) inhibits the intrinsic peroxidase-like activity of PB NCs by reducing Prussian Blue nanocrystals(PB NCs) to form inactive Prussian White (PW).

Determination of prostate cancer biomarker acid phosphatase at a copper phthalocyanine-modified screen printed gold transducer

In this work, a novel sensor based on immobilised copper phthalocyanine, 2,9,16,23-tetracarboxylic acid-polyacrylamide (Cu(II)TC Pc-PAA) was developed for determination of acid phosphatase (ACP) levels in nanomolar quantities. Detection was based on the measurement of enzymatically generated phosphate, with initial studies focused on phosphate detection at a Cu(II)TC Pc-PAA modified screen-printed gold transducer. The sensor was characterised in relation to operational performance (pH, response time, stability, linearity, and sensitivity) and common anionic interferents (nitrate, sulphate, chloride, and perchlorate). The functionalised surface also facilitated rapid detection of the enzyme bi-product 2-naphthol over the range 5–3000 μM. Quantitation of ACP was demonstrated, realising a linear response range of 0.5–20 nM and LOD of 0.5 nM, which is within the clinical range for this prostate cancer biomarker.

Highly selective determination of acid phosphatase in biological samples using a biomimetic recognition-based SERS sensor

In this paper, we introduce a synthetic biomimetic receptors-based surface enhanced Raman scattering (SERS) sensor for highly specific recognition and detection of acid phosphatase in complex biological samples. It depends on the establishment of molecular imprinted polymers (MIPs) which capture the target glycoprotein via biomimetic recognition, and SERS probes which bind to glycoproteins by boronate affinity. The MIPs layer was synthesized through self-polymerization of dopamine on the surface of glycoprotein-immobilized polymeric skeletons, which was prepared by choosing 4-vinylphenylboronic acid (VPBA) as functional monomers, pentaerythritol triacrylate (PETA) as crosslinker, ethyleneglycol (EG) and cyclohexanol as porogens. The accessible and stable recognition sites allowed the rebinding of the template and offered good reproducibility. The proposed biomimetic recognition-based SERS sensor showed superb performances for acid phosphatase detection with high sensitivity (LOD of 0.1 ng mL−1) and excellent selectivity.

Biomarcadores para la identificación y determinación del tiempo postcoital

The consummation of the unwanted sexual act or rape is a public health problem in the country. The search for sperm in the vagina or clothing by microscopy, the determination of acid phosphatase, the search for the prosthetic antigen and genetic tests are some tests to confirm a violation. However, the washing of the genital areas, the lability of the molecules that are measured, the insufficient amount of biological material and the high cost of some tests, prevent confirming the aggression, so identifying biological samples or presumptive spots of seminal fluid It is of the utmost importance. The search for biological material in case of violation can be done by light microscopy, determination of acid phosphatase, chromatography, prosthetic antigen search and genetic analysis. This review aims to group and examine the main methodologies for this purpose.

A simple assay for direct colorimetric detection of prostatic acid phosphatase (PAP) at fg levels using biphosphonated loaded PEGylated gold nanoparticles

A fast and sensitive colorimetric assay for the determination of prostatic acid phosphatase (PAP) levels using biphosphonates-PEG-coated gold nanoparticles (BP-PEG-AuNPs) has been developed. Addition of different amounts of PAP to the AuNPs results in a significant change of color, from a red-wine color to purple, and finally to blue. The PAP should bind onto the AuNPs surface and crosslink the AuNPs inducing their aggregation and as a consequence a color change of the solution from wine red to purple/blue. The color change was monitored by UV–vis spectrophotometry or with the naked eye. The ensuing concentration-dependent red-shift of surface plasmon resonance absorption allows the determination concentration within the fg range in 10 min. Importantly, the visual detection limit (1 ng/mL) allows the rapid differential diagnosis with naked eye or image analyzer. This demonstrates that the color modification observed with BP-PEG-AuNP is effectively due to an interaction between PAP and BP.

Lysozyme-stabilized bimetallic gold/silver nanoclusters as a turn-on fluorescent probe for determination of ascorbic acid and acid phosphatase

Bimetallic gold/silver nanoclusters were synthesized in aqueous solution with lysozyme as a stabilizing and reducing agent.

Near-infrared fluorescence probe for the determination of acid phosphatase and imaging of prostate cancer cells.

In this paper, we developed a near-infrared mercaptopropionic acid (MPA)-capped CuInS2 quantum dot (QD) fluorescence probe for the detection of acid phosphatases (ACP), which is an important biomarker and indicator of prostate cancer. The fluorescence of CuInS2 QDs could be quenched by Cu(2+), and then the addition of adenosine-5'-triphosphate (ATP) could effectively turn on the quenched fluorescence due to the strong interaction between Cu(2+) and ATP. The ACP could catalyze the hydrolysis of ATP, which would disassemble the complex of Cu(2+)-ATP. Therefore, the recovered fluorescence could be quenched again by the addition of ACP. In our method, the limit of detection (LOD) is considerably low for ACP detection in solution. Using the CuInS2 QDs fluorescence probe, we successfully performed in vitro imaging of human prostate cancer cells.

Effect of B-success herbal supplement on the accessory sex organs of male albino rats

This work investigated the effect of B-success herbal supplement on the accessory sex organs of male albino rats. Twenty weights matched male albino rats were divided into four groups of five rats and were given0.00, 315,630,945 mg/kg of the herbal product orally for 90 days. Animals had access to deionized water and were fed ad libitum with rat chow for 90 days. The feed and fluid consumption of the animals were measuredon daily basis while the body weight was measured weekly. Animals were anaesthetized after 90 days, bled sacrificed, epididymis, seminal vesicle and prostate were excised and weighed, protein, DNA. The epididymaltissues were also used for the determination of acid phosphatase and alkaline phosphatase. The result shows that there was significant (P. 0.05) decrease in both absolute and relative weights of seminal vesicle, prostateand epididymis in all the treated animals when compared with the control. The epididymal acid and alkaline phosphatase contents and semen count decreased significantly (p. 0.05) in all the treated animals when compared with the control. The DNA and protein contents of seminal vesicle (SV), prostate (P) and epididymis (E) of albino rats treated with the B-success herbal supplement decreased significantly (p. 0.05) in all the treated animals when compared with the control. B-success herbal supplement may have toxic effect on the accessory sex organs of male albino rats.Keywords: B–success herbal supplement, seminal vesicle (SV), prostate (P) and epididymis (E), male albino rats.

Barcode lateral flow immunochromatographic strip for prostate acid phosphatase determination

A barcode semiquantitative lateral flow immunochromatographic strip for prostate acid phosphatase (PAP) was developed, in which the monoclonal antibody specific for PAP was labeled to gold nanoparticle and another monoclonal antibody was immobilized on nitrocellulose membrane in the barcode fashion respectively. Based on the stepwise capture of analyte, the system expresses the concentration of PAP in nanogram range as four distinct ladder bars in 30 min, therefore, which could be detected directly by naked eye or image analyzer. Serum PAP from 65 patients was detected with this method and compared with enzyme linked immunosorbent assay (ELISA). There is a good agreement between the methods. Its easily readable result, and also its simplicity and low cost offers an alternative for testing PAP. By incorporating with different specific antibody, the assay can be further extended to detect a variety of analytes with clinical importance.

Alterations in serum tartrate-resistant acid phosphatase and C-terminal telopeptide of type I collagen in experimental canine osteotomies fixed using 2 different techniques

The aim of the present study was to monitor serum tartrate-resistant acid phosphatase (TRAP) and C-terminal telopeptide fragments of type I collagen (CTX) over time in canine experimental osteotomies fixed using 2 osteosynthesis techniques, to determine the relevance of both markers in monitoring bone healing, and to investigate the influence of the 2 osteosynthesis techniques on their concentrations. Transperiosteal osteotomy of the diaphyses of the right tibia and fibula was performed in 12 dogs. The dogs were then randomly assigned to 1 of 2 groups: group 1 (6 dogs) underwent osteotomy fixed with intramedullary osteosynthesis (IMO) and group 2 (6 dogs) underwent osteotomy fixed with a plate (plate osteosynthesis [PLO]). Craniocaudal radiographs were obtained immediately after osteosynthesis, 2 weeks post-surgery and 1, 2, 3, 4, 5, and 6 months post-surgery. The evaluation of bone resorption was performed visually using a 4-grade scoring system. At the same time points, venous blood was sampled for determination of tartrate-resistant acid phosphatase and the concentration of C-terminal telopeptide fragments of type I collagen. Radiologically visible bone resorption was characterized by 2 peaks. The 1st peak occurred by the end of the 2nd postoperative week with both osteosynthesis methods (P < 0.001). The 2nd peak began by the end of the 4th postoperative month and persisted until the end of the experiment. Serum TRAP was not a reliable marker of bone resorption during the study period. CTX concentrations increased considerably in both groups by the end of the 1st postoperative month (P < 0.05), decreased by the 3rd postoperative month, and increased again by the end of the 5th postoperative month. CTX, therefore, could be used to monitor normal bone healing.

Autophagy plays a potential role in the process of sea cucumber body wall “melting” induced by UV irradiation

The changes of tissue appearances and structures in the process of UV-induced “melting” for sea cucumber (Stichopus japonicus) body wall were studied. And the localization and determination of acid phosphatase (ACP), Cathepsin B and Cathepsin L activities were also investigated. The results show that the connective tissue was damaged with many hollows emerging and the regular collagen bundles were broken apart into irregular fragments. Margination of condensed chromatin at the nuclear membrane was observed. Both Golgi’s body and endoplasmic reticulum swelled, curled, and eventually double-or multi-lamellar vesicles were formed. A number of autophagic vesicles distributed in all through the whole cytoplasm. ACP becomes more active after UV irradiation. The activities of cathepsin B and cathepsin L increased in UV-treated sea cucumbers and both achieved their maximum under certain conditions. It indicates that autophagy plays a potential role in the “melting” process for sea cucumber body wall induced by UV irradiation.

A dual fluorophore system for simultaneous bioassays

A detection scheme for the simultaneous evaluation of two bioassays based on fluorescence spectroscopy is presented. For the determination of hydrogen peroxide-generating enzymes or peroxidases, the non-fluorescent 4-( N-methylhydrazino)-7-nitro-2,1,3-benzooxadiazole (MNBDH) is converted to the strongly fluorescent 4-( N-methylamino)-7-nitro-2,1,3-benzooxadiazole (MNBDA). Phosphatases are detected based on the cleavage of the non-fluorescent 5-fluorosalicyl phosphate (5-FSAP) under formation of the fluorescent 5-fluorosalicylic acid (5-FSA). While excitation of the fluorophores may be carried out at the same wavelength, their emission spectra differ significantly. This allows the read-out of both assays using commercially available microplate readers without additional chemometric tools. Compared with individual assays, limits of detection are similar, and linearity of the calibration functions for both enzymes is observed over 2–3 concentration decades starting at the limit of quantification. The simultaneous determination of glucose oxidase and acid phosphatase in honey is presented as example for the application of the detection scheme.