• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.135-144
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• 1999

Environmental toxicities of priority water pollutants were evaluated by two selected bioassays, Lettuce seed germination/elongation test and Microtox acute toxicity test. Toxic chemicals (heavy metals, polycyclic aromatic hydrocarbons, and phenolic compounds) inhibited the germination rate and root elongation of Lettuce seed, as well as the bioluminescence of Microtox bacteria. When test biota were exposed to target chemicals, the sensitivity of Lettuce bioassay was relatively lower than that of Microtox bioassay. However, Lettuce bioassay may be a good candidate for prescreening the environmental toxicities of priority water pollutants, since the testing method with Lettuce seed was relatively easier and more economic than with Microtox bacteria. Toxicity tests were conducted to compare the validity and sensitivity of both bioassays for sediment from a small stream passed through urban area as well as leachate from a municipal solid waste landfill. From experimental results, we found that Lettuce test and Microtox test are compensated each other as a battery of bioassay for evaluating the environmental toxicities of field samples obtained from a small stream contaminated by pollutants.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.382-390
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• 2018

The history of the pregnancy test started in ancient Egypt with a germination test using wheat and barley. Since then, unscientific methods have been used from the days of Hippocrates and Galen to the Middle Ages when uroscopy was used, even until the early 1800s. On the other hand, since the mid-1800s, scientific methods and evidence have begun to emerge, which led to scientific research on the physiological characteristics of pregnancy. The first attempt to utilize these scientific findings was initiated with the bioassay by Aschheim and Zondek using rats and mice in 1927, and then developed into experiments using rabbits and frogs. The immunoassay method, which started in the 1960s, contributed greatly to the generalization of the pregnancy tests while improving the problems of the bioassay. In 1976, a pregnancy test kit was introduced that can be used at home, contributing to the popularization of pregnancy tests. Since the 1980s, technological advances in diagnostic tests have also been applied to pregnancy tests to further improve the reliability of the diagnosis of pregnancy. In the 2000s, the accuracy and ease of use of the pregnancy test kits for home use have improved drastically. This study examined the history and scientific development of the pregnancy test.

• Journal of Radiation Protection and Research
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• v.39 no.2
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• pp.96-102
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• 2014

Urine bioassay has been widely used for internal dosimetry due to simple process of sampling and measurement. In this paper, we participated in the NRIP (NIST Radiochemistry Intercomparison Program) hosted by US NIST to carry out a reliable performance test of urine bioassay and introduced the measurement method and results of NRIP-2013. In customary exercise with 60 days of reporting time, bioassay results of 12 radionuclides in the synthetic urine samples were acceptable based on the performance criteria of ANSI N13.30. In emergency preparedness exercise with 8 hours of reporting time, bioassay results of 9 radionuclides showed that differences ranged from -35% to 45%. However, we concluded that urine bioassay applied for emergency preparedness exercise would be applicable for rapid screening and estimation of internal exposure within a difference of ${\pm}45%$ in the event of radiological accidents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s01
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• pp.16-25
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• 1989

A bioassay is a test system using a living organism (in whole or in part) to determine the presence or relative potency of chemical substances. The development and uses of bioassay are intimately linked to the discovery and characterization of the major classes of plant hormones. An application of this relationship is helpful for understanding the concept of plant hormones as well as the use of bioassay. And plant bioassay have been development and employed not only for the discovery and characterization of the biological activity of plant growth regulators but also have served several important secondary roles. The ideal bioassay should possess the characteristic of high specificity. great sensitivity. short response time, low cost and ease of obtaining plant material. acceptable ease of manipulation, and minimal space and equipment requirements.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.44-44
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• 1996

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.209-216
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• 1998

The present study was designed: (1) to determine whether or not hypoxia stimulates the release of endothelium-derived relaxing factors (EDRFs) from endothelial cells, and (2) to examine whether or not the hypoxia-induced EDRFs release is further augmented by previous hypoxia-reoxygenation, using bioassay system. In the bioassay experiment, rabbit aorta with endothelium was used as EDRFs donor vessel and rabbit carotid artery without endothelium as a bioassay test ring. The test ring was contracted by prostaglandin $F_{2{\alpha}}$ $(3{\times}10^{-6}\;M/L)$, which was added to the solution perfusing through the aortic segment. Hypoxia was evoked by switching the solution aerated with 95% $O_2/5%\;CO_2$ mixed gas to one aerated with 95% $N_2/5%\;CO_2$ mixed gas. When the contraction induced by prostaglandin $F_{2{\alpha}}$ reached a steady state, the solution was exchanged for hypoxic one. And then, hypoxia and reoxygenation were interchanged at intervals of 2 minutes (intermittent hypoxia). The endothelial cells were also exposed to single 10-minute hypoxia (continuous hypoxia). When the bioassay ring was superfused with the perfusate through intact aorta, hypoxia relaxed the precontracted bioassay test ring markedly. Whereas, when bioassay ring was superfused with the perfusate through denuded aorta or polyethylene tubing, hypoxia relaxed the precontracted ring slightly. The relaxation was not inhibited by indomethacin but by nitro-L-arginine or methylene blue. The hypoxia-induced relaxation was further augmented by previous hypoxia-reoxygenation and the magnitude of the relaxation by intermittent hypoxia was significantly greater than that of the relaxation by continuous hypoxia. The results suggest that hypoxia stimulates EDNO release from endothelial cells and that the hypoxia-induced EDNO release is further augmented by previous hypoxia-reoxygenation.

• Journal of Korean Society on Water Environment
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• v.20 no.1
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• pp.48-54
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• 2004

Two methods, a Ceriodaphnia algal uptake suppression test (CAUST) and a new toxicity test based on temperature control (TTBTC) which are based on feeding behaviour and temperature control, respectively, were developed and compared for the adoption as the better methodology for short-term toxicity screening. As previously published by Lee et aI., (1997), the CAUST method is based on the feeding behaviour of C. dubia and requires as little as 1 hour of contact time between C. dubia neonates and toxicant. However, even though CAUST requires only 1 hour of contact time, this method still take many hours for the preparation and measurement. Before the test starts, neonate digestive tracts were cleared by feeding yeast to the daphnids, Neonates were then exposed to toxicant, followed by addition of Scenedesmus subspiatus into the bioassay vessels. Daphnids were examined under the bright-field microscope with the presence of algae (indicated by a green colored digestive tract) or the absence of algae. Uptake indicated no toxic effect, whereas, absence of uptake indicated toxic inhibition. Unlike CAUST, the newly developed method (TTBTC) is based on just temperature control for the toxicity test of C. dubia. Initially, neonates are exposed to toxicants while the temperature of water bath containing media increased to $35.5^{\circ}C$. After 1.25 hour of contact time, the number of the daphnids, either live (no toxic effect) or dead (toxic effect), is counted without the aid of any instrument. In both methods, median effective concentrations ($EC_{50}$ values) were computed based on the results over a range of dosed toxicant concentrations. It showed that TTBTC was as sensitive as the standard 48-hour acute bioassay and CAUST. TTBTC and CAUST were much more sensitive than the I-hour I.Q. test and 30-minute Microtox. This study indicates that TTBTC is an easier and more rapid toxicity test than the standard 48-hour acute bioassay and even CAUST.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.158-158
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• 2003

Bioassays using gametes of sea urchins are widely used in ecotoxicological assessments of marine environments. Since most of sea urchin species in Korean coastal water spawn from spring to autumn, bioassay with them during the winter is impossible. In the course of developing standard methods for bioassays with Korean species, we found a winter-spawning starfish, Asterias amurensis, Since reproductive mode of asteroids is similar to echinoids, the bioassay protocol for sea urchins could be applied similarly to the starfish. Here, we tested and determined several conditions for the acceptability of bioassay with A. amurensis. The least required time for formation of fertilization membrane of fertilized eggs to be easily distinguished from unfertilized ones was 60 min. The threshold of sperm to egg ratio that could make acceptable fertilization rates in controls was 3000. The allowed time for manipulation of sperm after dilution in seawater was at most 3 hr. The optimal exposure time of sperms when the response against toxicant solution was relatively stable was in the range of 20-60 min. The tolerance range of sperms to the salinity of test solution was 26-38 psu. The sensitivity of A. amurensis sperm was intermediate among marine organisms commonly used in aquatic toxicity tests. The sperm bioassay with A. amurensis can be satisfactorily applied to toxicity assessments of marine environments.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.19-26
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• 2010

Discharged materials from the point or non-point source are released into the sea, and as the results, marine environment is directly affected. We must estimate the impacts of contaminants to marine pollution rapidly and accurately. Therefore, it is needed on early warning system for appreciating marine environmental impacts, and required a bioassay to evaluate abnormal changes. A bioassay test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine annimals. We have studied the effects of metals on early development of a sea urchin species, Strongylocentrotus intermedius. S. intermedius embryos were tested with six metals (Cu, Ag, Zn, Cd, Cr, Ni) and showed the highest sensitivity to Cu as well as the lowest sensitivity to Cd. The order of biological impact for metals was Cu>Ag>Ni>Zn>Cr>Cd. In accordance with the results, sea urchins embryos can provide biological criteria for seawater quality assessment. The sensitivity of developmental bioassay whith S. intermedius is at intermediate level among marine organisms commonly used in aquatic bioassays. And this sea urchin can be routinely employed as a test organism for ecotoxicity assays.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.191-197
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• 2005

A new method, ToxTemp (TOXcity test based on TEMPerature control) using Ceridaphnia dubia was applied to evaluate the toxicity of insecticide materials and compared with the standard 48 hr acute bioassay. BPMC, diazinon and fenitrothion may cause the inhibition to the biological process in sewage treatment plant and need to detect toxicity within short contact time. The ToxTemp method showed sensitive detection with more shorter contact of 1-1.5 hr time than that of the standard 48 hr acute bioassay. To evaluate toxicity of real wastewater/sewage, the inhibition rate of nitrification and oxygen uptake rate (OUR) using activated sludge, the standard 48hr acute bioassay and ToxTemp method using C. dubia were compared, respectively. On the basis of the inhibition rate of nitrification, the OUR test showed the less sensitive results at the relatively strong toxic sewage. On the other hands, the standard 48hr acute bioassay and ToxTemp method using C. dubia represented the toxicity of each wastewater/sewage with high sensitivity. Even the slightly low (about 1.5%) sensitivity, the ToxTemp method showed the high applicability to the real site of sewage treatment plant.