• Toxicological Research
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• 제16권2호
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• pp.101-107
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• 2000

Cannabidiol derivatives (1, 2 and 3), 5-fluorouracil (4, 5-FU) and adriamycin (5, AM) were tested for their growth inhibitory effects against human tumor cell lines using two different 3-{4,5-dimeth-ylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and sulforhodamine B protein (SRB) assay. The light microscopic study showed morphological changes of the treated cells. Disruptions in cell organelles were determined by colorimetric methods; MTT assay and STB assay. These results suggest that cannabidiol (1, CBD) retains the most growth-inhibitory activity against human tumor cell lines.

• KSBB Journal
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• 제23권6호
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• pp.484-488
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• 2008

본 연구에서는 peroxidase 활성의 신속한 스크리닝을 위해 peroxidase의 활성을 정량적으로 평가할 수 있는 분석으로 agar plate와 96-well plate에서 peroxdase의 활성에 비례하여 색상감도를 측정할 수 있는 colorimetric 분석법을 개발하였다. 이 방법은 RP-HPLC 결과와 매우 비례적으로 상관적인 결과를 보였다. 이 colorimetric 분석법을 사용하여, 폐수에서 한천 고체배지에서 7회에 걸친 스크리닝으로 높은 농도의 2,4-DCP(1000 ppm)에서 생존하는 균주를 스크리닝하였고 선별된 이들 균주들은 탄소원으로 2,4-DCP 만을 대사할 수 있으며 높은 peroxidase 생산량을 보였다. 분리된 균주들 중 높은 peroxidase 활성을 가지는 2,4-DCP 분해 균주를 분리하였고 최종 분리된 균주는 염색폐수의 COD를 4시간 동안 44%에서 61%까지 제거하였다. 상기의 결과에 의해 본 연구에서 개발된 발색법이 페놀화합물 분해 균주 스크리닝법이 빠르고 쉬운 난분해성 물질인 페놀 혼합물의 분해 균주 탐색에 대하여 성공적으로 적용될 수 있기를 기대한다.

• Journal of Microbiology and Biotechnology
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• 제31권4호
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• pp.501-509
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• 2021

More than half the world's population is thought to be infected with Helicobacter pylori. Although the majority of infected people are asymptomatic, H. pylori infection may cause gastric ulcers and deadly gastric cancer. Owing to the difficulty and invasiveness of current routine culture and diagnostic methods, a highly sensitive and specific noninvasive assay for H. pylori is of interest. This study highlighted the design and performance of a colorimetric magneto loop-mediated isothermal amplification (CM-LAMP) assay to detect H. pylori in spiked saliva samples. LF primers were coated on magnetic nanoparticles by carbodiimide-induced immobilization and functionally used for solid-phase amplification. During the LAMP reaction at 66℃, biotin-tagged FIPs were incorporated into LAMP amplicons. The colorimetric signal developed after the addition of NeutrAvidin horseradish peroxidase conjugate (NA-HRP) and ABTS. None of the tested microorganisms, including closely related bacteria, was shown positive by the CM-LAMP assay except H. pylori isolates. This novel platform was highly specific and 100-fold more sensitive (40 CFU/ml or 0.2 CFU per reaction) than the PCR and conventional LAMP assays for the detection of H. pylori in spiked saliva. Our results demonstrated the feasibility of using this noninvasive molecular diagnostic test to detect H. pylori in saliva samples.

• 대한의생명과학회지
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• 제10권3호
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• pp.263-268
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• 2004

This study was carried out to evaluate the cytotoxic effect of phenolic compound on normal NIH 3T3 fibrolasts. The colorimetric assay for phenol compound, syringic acid was performed by MTT assay or XTT assay. MTT or XTT assays are known as a very sensitive method in measuring the cytotoxic effect of chemical agents in vitro. In the present study, syringic acid on normal Nlli 3T3 fibroblasts did not show any cytotoxicity for MTT assay or XTT assay compared with control after cells were treated with various concentrations of syringic acid for 48 hours. MTT/sub 50/ and XTT/sub 50/ were 3,340.9 μM and 2,462.4 μM of syringic acid, respectively. From the above the results, it is suggested that phenolic compound of syringic acid did not have any cytotoxicity on normal NIH 3T3 fibroblasts.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2110-2115
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• 2015

A liquid-based colorimetric assay using a pH indicator was introduced for high-throughput monitoring of lysine decarboxylase activity. The assay is based on the color change of bromocresol purple, measured at 595 nm in liquid reaction mixture, due to an increase of pH by the production of cadaverine. Bromocresol purple was selected as the indicator because it has higher sensitivity than bromothymol blue and pheonol red within a broad range and shows good linearity within the applied pH. We applied this for simple determination of lysine decarboxylase reusability using 96-well plates, and optimization of conditions for enzyme overexpression with different concentrations of IPTG on lysine decarboxylase. This assay is expected to be applied for monitoring and quantifying the liquid-based enzyme reaction in biotransformation of decarboxylase in a high-throughput way.

• 대한화학회지
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• 제42권4호
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• pp.411-415
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• 1998

인체 피부흑색종 세포에 대한 epigallocatechin gallate의 세포독성작용을 평가하고, 광학현미경적 관찰을 실시하여 인체 피부흑색종 세포의 형태학적인 변화를 볼 수 있었다. 세포독성은 비색정량분석법, NR정량분석법과 SRB정량분석법으로 측정하였다. 이런 결과는 epigallocatechin gallate에 항암활성을 보여준다.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1322-1327
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• 2024

The accurate and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) holds significant clinical importance. This work presents a new method for detecting methicillin-resistant Staphylococcus aureus (S. aureus) in clinical samples. The method uses an aptamer-based colorimetric assay that combines a recognizing probe to identify the target and split DNAzyme to amplify the signal, resulting in a highly sensitive and direct analysis of methicillin-resistance. The identification of the PBP2a protein on the membrane of S. aureus in clinical samples leads to the allosterism of the recognizing probe, and thus provides a template for the proximity ligation of split DNAzyme. The proximity ligation of split DNAzyme forms an intact DNAzyme to identify the loop section in the L probe and generates a nicking site to release the loop sequence ("3" and "4" fragments). The "3" and "4" fragments forms an intact sequence to induce the catalytic hairpin assembly, exposing the G-rich section. The released the G-rich sequence of LR probe induces the formation of G-quadruplex-hemin DNAzyme as a colorimetric signal readout. The absorption intensity demonstrated a strong linear association with the logarithm of the S. aureus concentration across a wide range of 5 orders of magnitude dynamic range under the optimized experimental parameters. The limit of detection was calculated to be 23 CFU/ml and the method showed high selectivity for MRSA.

• Archives of Pharmacal Research
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• 제27권9호
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• pp.968-972
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• 2004

A 1, 2-diglyceride-based multi-step colorimetric assay to measure the pancreatic lipase activ-ity was applied for the determination of the kinetic profiles of the lipase inhibition with a slight modification and the validity verification. With this assay method, our study revealed that platy-codin D, one of major constituents of Platycodi Radix, inhibits the pancreatic lipase activity in a competitive type, with the value of $K_1$ being 0.18${\pm}$0.02 mM. In addition, PO has affected the val-ues of $K_{m}$, app/ and $K_{cat}$/$K_{m}$ in a dose-dependent manner. The results shed a meaningful light on how PO mediates lipid metabolism in the intestinal tracts. On the other hand, since the revised assay is sensitive, rapid, and does not affect the accuracy to the kinetic properties, it is applica-ble not only to evaluation of the kinetic properties of the pancreatic lipase, but also to high-throughput screening of pancreatic lipase activity.

• Archives of Pharmacal Research
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• 제27권10호
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• pp.1048-1052
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• 2004

A 1, 2-diglyceride-based multi-step colorimetric assay to measure the pancreatic lipase activity was applied for the determination of the kinetic profiles of the lipase inhibition with a slight modification and the validity verification. With this assay method, our study revealed that platycodin D, one of major constituents of Platycodi Radix, inhibits the pancreatic lipase activity in a competitive type, with the value of $K_I$ being 0.18${\pm}$0.02 mM. In addition, PD has affected the values of $K_{m,app}\;and\;K_{cat}/K_m$ in a dose- dependent manner. The results shed a meaningful light on how PD mediates lipid metabolism in the intestinal tracts. On the other hand, since the revised assay is sensitive, rapid, and does not affect the accuracy to the kinetic properties, it is applicable not only to evaluation of the kinetic properties of the pancreatic lipase, but also to highthroughput screening of pancreatic lipase activity.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2485-2488
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• 2009