• Journal of Microbiology
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• 제44권1호
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• pp.72-76
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• 2006

Plasma-derived products are produced from plasma via fractionation and chromatography techniques, but can also be produced by other methods. In the performance of nucleic acid amplification tests (NAT) with plasma-derived products, it is necessary to include an internal control for the monitoring of all procedures. In order to avoid false negative results, we confirmed the usefulness of the bovine viral diarrhoea virus (BVDV) for use as an internal control in the detection of hepatitis C virus (HCV) RNA in plasma-derived products. These products, which were spiked with BVDV, were extracted and then NAT was performed. Specificity and sensitivity were determined via the adjustment of primer concentrations and annealing temperatures. BVDV detection allows for validation in the extraction, reverse transcription, and amplification techniques used for HCV detection in plasma-derived products.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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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)

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2004년도 KSOT/KEMS Fall Annual Meeting
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• pp.108-109
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• 2004

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.745-750
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• 2004

The objective of this collaborative study was to establish a Korean standard of Japanese encephalitis (JE) vaccine (mouse brain-derived, formalin-inactivated) for potency assay. A candidate preparation proposed as a Korean standard was provided by GreenCross Vaccine, and six laboratories, including one national control laboratory and five manufacturers of JE vaccine, participated in the study. The potency of the candidate preparation and a reference standard obtained from Japan was estimated by mouse immunogenicity assay using the in vitro plaque reduction neutralization test (PRNT). The results of 72 assays conducted by the 6 laboratories showed that the overall mean potency estimate of the candidate preparation was 2.455 log median plaque reduction neutralization antibody titer per 0.5-ml dosage administered twice in mice at 7-day intervals, and that the mean potency ratio of the candidate preparation relative to the reference standard was 1.074. The potency estimates were quite variable among laboratories irrespective of the preparation. The variability of assays assessed by Z scores and coefficient of variation (CV) were in general within the level of acceptance (Z scores within $\pm3$ and $CV\;\leq\;15%$). Therefore, we concluded that the candidate preparation would be suitable as a national standard for testing the potency of JE vaccine (inactivated).

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.595-602
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• 2005

A one-step real-time quantitative RT-PCR assay in combination with automated RNA extraction was evaluated for routine testing of HCV RNA in the laboratory. Specific primers and probes were developed to detect 302 bp on 5'-UTR of HCV RNA. The assay was able to quantitate a dynamic linear range of $10^7-10^1$ HCV RNA copies/reaction ($R^2=0.997$). The synthetic HCV RNA standard of $1.84{\pm}0.1\;(mean{\pm}SD)$ copies developed in this study corresponded to 1 international unit (IU) of WHO International Standard for HCV RNA (96/790 I). The detection limit of the assay was 3 RNA copies/reaction (81 IU/ml) in plasma samples. The assay was comparable to the Amplicor HCV Monitor (Monitor) assay with correlation coefficient r=0.985, but was more sensitive than the Monitor assay. The assay could be completed within 3 h from RNA extraction to detection and data analysis for up to 32 samples. It allowed rapid RNA extraction, detection, and quantitation of HCV RNA in plasma samples. The method provided sufficient sensitivity and reproducibility and proved to be fast and labor-saving, so that it was suitable for high throughput HCV RNA test.

• Osong Public Health and Research Perspectives
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• 제8권6호
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• pp.389-396
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• 2017

Objectives: To circumvent the limitations of the current golden standard method, colony-forming unit (CFU) assay, for viability of Bacille Calmette-$Gu{\acute{e}}rin$ (BCG) vaccines, we developed a new method to rapidly and accurately determine the potency of BCG vaccines. Methods: Based on flow cytometry (FACS) and fluorescein diacetate (FDA) as the most appropriate fluorescent staining reagent, 17 lots of BCG vaccines for percutaneous administration and 5 lots of BCG vaccines for intradermal administration were analyzed in this study. The percentage of viable cells measured by flow cytometry along with the total number of organisms in BCG vaccines, as determined on a cell counter, was used to quantify the number of viable cells. Results: Pearson correlation coefficients of FACS and CFU assays for percutaneous and intradermal BCG vaccines were 0.6962 and 0.7428, respectively, indicating a high correlation. The coefficient of variation value of the FACS assay was less than 7%, which was 11 times lower than that of the CFU assay. Conclusion: This study contributes to the evaluation of new potency test method for FACS-based determination of viable cells in BCG vaccines. Accordingly, quality control of BCG vaccines can be significantly improved.

• Toxicological Research
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• 제33권3호
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• pp.225-231
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• 2017

National reference standards (NRSs) for biologics are established through potency estimation by a multi-center joint study of standard materials used in the approval process for national lot release and quality control of vaccines, blood products, and other biologics. In this study, a stability evaluation was conducted to determine whether the potency of NRSs for six blood products was being maintained at a consistent level in Korea. The present study conducted real-time stability tests via in-vivo/in-vitro bioassay on NRSs for blood coagulation factor VIII concentrate (2nd standard), antithrombin concentrate, prekallikrein activator, anti-hepatitis B immunoglobulin, blood coagulation factor IX concentrate, and anti-tetanus human immunoglobulin, as well as a trend analysis using cumulative annual results. The real-time stability test results showed that the mean potency of six NRSs was all within the control limit. In the trend analysis, the potency of NRS for blood coagulation factor VIII concentrate (2nd standard) showed a decreasing trend, while the potency of all other products had been stably maintained. The present study confirmed that the mean potency of NRSs for six blood products had been stably maintained in Korea. The findings of the present study establish a foundation that can ensure the quality of NRSs for biologics in Korea, and it is expected to make a major contribution to the supply of high-quality biologics.

• Osong Public Health and Research Perspectives
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• 제9권6호
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• pp.363-363
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• 2018

• Molecules and Cells
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• 제45권5호
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• pp.284-290
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• 2022

Exosome, a type of nanoparticles also known as small extracellular vesicles are gaining attention as novel therapeutics for various diseases because of their ability to deliver genetic or bioactive molecules to recipient cells. Although many pharmaceutical companies are gradually developing exosome therapeutics, numerous hurdles remain regarding manufacture of clinical-grade exosomes for therapeutic use. In this mini-review, we will discuss the manufacturing challenges of therapeutic exosomes, including cell line development, upstream cell culture, and downstream purification process. In addition, developing proper formulations for exosome storage and, establishing good manufacturing practice facility for producing therapeutic exosomes remains as challenges for developing clinical-grade exosomes. However, owing to the lack of consensus regarding the guidelines for manufacturing therapeutic exosomes, close communication between regulators and companies is required for the successful development of exosome therapeutics. This review shares the challenges and perspectives regarding the manufacture and quality control of clinical grade exosomes.

• 대한바이러스학회지
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• 제30권2호
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• pp.113-124
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• 2000

We had isolated 8 viruses from 91 specimen collected at southwest Cheju Province during early spring 1998 and 2 viruses from 9 specimen collected at Chung Nam Province during early spring 1999. To perform cross-reactivity among 4 mumps vaccine strains and 10 wild-type mumps viruse isolates, we immunized mice and took antisera against each virus. There were no antibody titer differences by indirect immunofluorescence assay (IFA), but most isolated mumps viruses showed a little cross-reactivities with Jeryl Lynn and Rubini strains. It has shown similar result by haemagglutination-inhibition (HAI) test. These results show that 4 mumps strains used as vaccine have the protection ability against endemic wild-type mumps viruses. Also the SH gene analysis was performed to identify genotypes. Most isolated mumps viruses belonged to genotype D. These results indicate that endemic mumps viruses in Korea are different to ones isolated in Japan and China.