• Proceedings of the PSK Conference
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• 2002.10a
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• pp.328.3-329
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• 2002

A convenient bioassay of nerve growth factor(NGF) is essential for assessing its potency during the course of product development and quality controls afterwards. We have set up a cell-based bioassay for determining the potency of recombinant NGF using rat pheochromocytoma (PC12) cells. Cell survival was measured by monitoring the reduction of the alamarBlue$^{TM}$ dye by living cells. (omitted)d)

• Journal of Life Science
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• v.9 no.6
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• pp.653-658
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• 1999

A novel marine microorganism, Vibrio sp. YE-101, was isolated from pufferfish and investigated for its ability to synthesize tetrodotoxin (TTX). Various strains isolated from the intestine of pufferfish were grown on TCBS agar plate, and then cultured on Ocean Research Institute (ORI) medium supplemented with 3% NaCl at 23$^{\circ}C$ for 3days. The cells were harvested, disrupted, fractionated by Bio-Gel P-2 column chromatography and then TTX-producing strain, Vibrio sp. YE-101, was identified using mouse bioassay. The isolated TTX from Vibrio sp. YE-101 was also analyzed and identified by HPLC and gas chromatography-mass spectrometer (GC-MS). The mass fragmentation of trimethylsilyl derivatives of C9-base of TTX from Vibrio sp. YE-101 was interpreted and the pattern of fragmentation was same with that of authentic standard. The purfied TTX was also positive to the mouse bioassay, which clearly represents that Vibrio sp. YE-101 can synthesize TTX.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.411-414
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• 2002

Acylated homoserine lactones (AHLs) are membrane-permeant signal molecules responsible for biofilm formation of gram-negative bacteria via a unique mechanism known as quorum sensing. A target specific bioassay employing the AHL-responsive Agrobacterium tumefaciens reporter strain has been developed to identify new AHL-like compounds from natural products, which could be developed into antifouling compounds. By varying the X-gal concentration, incubation time, solvent for sample preparation and the sample loading procedure, it was possible to detect low level AHLs up to $10^1nM$. The length of the acyl chain of the AHLs was found to affect the sensitivity of this bioassay.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.24-34
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• 1981

For bioassay of the various extracts of ginseng, the growth determination method using Saccharomyces cerevisiae which was cultured with various doses of the extracts, was studied The water extract, Powder. and ethanol extract were more effective (about 45∼ 110% increase) than saponins or its fractions (about 20∼35% increase). The cold methanol residue showed a increase effect but it was not significant. The bioassay curves for the water extract, ethanol extract, the butanol extracted saponins and the cold methanol- residue were made from the experimental data. From these curves it is possible to find the relation between dose and effectiveness and the optimal doses of various ginseng extracts, and the amount of extract in a sample can be estimated The .angers of sample amount were 0.01% (100ppm) ∼0.32% (3200ppm) fo. the water extract, 0.025% (150ppm)∼0.1% (1000ppm) for the ethanol extract, and 0.008% (80ppm)∼0.016% (160ppm) for the saponins. It was impossible to determine the range for the cold methanol- residue, The acceleration effects on the cell proliferation by a only 0.0008% (8ppm) of the diol- and triol-saponin were measurable in earlier Period (24 hour treatment).

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.46-50
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• 1996

Tritium dose management is an important aspect of the radiation protection program at CANDU type reactor sites. This paper describes the bioassay and dosimetry of tritium at CANDU reactor sites, especially for Wolsung Nuclear Power Plant. It presents a compilation of information drawn from published papers, technical reports, international and national guidelines as well as practical experience both in Korean and Canadian CANDU Nuclear Power Plants. The implementation of this program would provide a technical basis for demonstrating to workers, managers and regulators that tritium bioassay measurements, dose calculations and records should be of acceptable quality and should meet overall radiation protection program objectives.

• The Korean Journal of Pharmacology
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• v.11 no.2
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• pp.41-46
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• 1975

The isolated strips of tortoise intestine are evaluated as a test organ for bioassay of prostaglandin $E_1$. This preparation responded highly sensitively to $PGE_1$ and $PGE_2$ in picogram concentration range. The mean slope and the value of precision index among the doses of 0.1, 0.3 and 0.5ng/ml in final concentration were 37.7 and 0.143, respectively. And this was relatively insensitive to different prostaglandins; $E_1/E_2{\gtrsim}1$, $E_1/A_2{\sim}50$ and $E_1/F_{2\alpha}{\sim}100$, and showed the dual responses to 5-hydroxytryptamine and histamine; initial contraction followed by relaxation. The dose-ratio inducing the relative equal contraction height for $PGE_1$, acetylcholine, caerulein, angiotensin and barium chloride was 0.4 : 50 : 25 : 10 : 100 in this order. These results suggest that the intestinal strips of the tortoise are suitable for bioassay of prostaglandin $E_1$ and $E_2$ between the doses of 0.1 and 1.0 ng/ml level in the tissue extracts.

• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.71-75
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• 1998

Carbendazim, which is widely used fungicide, was investigated for rat hepatocarcinogenesis using a medium-term carcinogenicity bioassay. All rats were initially given a single dose (200mg/kg) of diethylnitrosamine (DEN) i.p. and then, starting 2 weeks later, carbendazim treatment group and positive control group received carbendazim (7 mg/kg/ day) and 2-acetylaminofluorene (2-AAF, 1%), respectively, in the diet for 6 weeks. All rats were subjected to two-thirds partial hepatectomy (PH) at week 3 and sacrificed at week 8. Carcinogenic potential was scored by comparing the number and area per cm$^2$ of induced glutathione-S-transferase placental form (GST-P) positive foci in the liver. Carbendazim had no effect in the increase of body weight, hematological and biochemical values, and the number and area of GST-P positive loci. These results suggest that this bioassay using DEN-PH method can be useful for detection of hepatocarcinogenic potentials of pesticide.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.182-185
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• 2009

Amoora cucullata (Meliaceae), a mangrove plant, has folkloric reputation as a medicinal agent in Bangladesh. In this study, the n-hexane, ethyl acetate and methanolic extracts of the stem bark of this plant were subjected to microbiological investigation and brine shrimp lethality bioassay. In case of antimicrobial screening, the ethyl acetate and methanolic extracts appeared to be potent in terms of both zone of inhibition and spectrum of activity showing the average zones of inhibition 8 - 14 mm and 9 - 16 mm, respectively. In the brine shrimp lethality bioassay, the methanolic extract demonstrated highest cytotoxicity having $LC_{50}$ of $0.549{\mu}g/ml$, whereas the ethyl acetate and n-hexane extract showed $LC_{50}$ of 7.943 and $17.180{\mu}g/ml$, respectively.

• Korean Journal of Pharmacognosy
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• v.24 no.3
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• pp.263-265
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• 1993

Brine shrimp toxicity of water extracts of twenty three crude drugs was tested by the brine shrimp bioassay. Eight crude drugs were shown to have 100% mortality in $1000{\;}{\mu}g/ml$. They were fractionated by Amberlite XAD-2 column chromatography and were tested by the brine shrimp bioassay. Methanol fraction of Rhei Rhizoma $(LC_{50}=49.60{\;}{\mu}g/ml)$ and Cantharis $(LC_{50}=54.08{\;}{\mu}g/ml)$ were shown to have potent brine shrimp toxicity in this test.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.360-365
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• 2008

For the screening of residual antibiotics in foods, bioassays and microbiological inhibitor tests are commonly applied. These methods are tested by the various susceptibility of bacteria against different kinds of antibiotics. However, the sensitivity of bioassay is generally insufficient to detect some residual antibiotics at level of interest. This study was performed to investigate the detection limit of variable antibiotics of the bioassay and to improve the sensitivity to some antibiotics. The sensitivity of bioassay using Bacillus megaterium ATCC 9885, B. subtilis ATCC 6633, B. cereus ATCC 11778 and Geobacillus stearothermophilus ATCC 10149 was low in the detection of macrolides, quinolones, chloramphenicol, and monensin. On the contrary, Micrococcus luteus ATCC 9341 showed high sensitivity to macrolides and Escherichia coli ATCC 11303 was highly sensitive to quinolones and aminoglycosides. Consequently, both strains would be useful to improve sensitivity of bioassay with a wide detection range.