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Updated: Jun 9, 2026
Chemically-blocked Antibody Microarray for Multiplexed High-throughput Profiling of Specific Protein Glycosylation in Complex Samples
Published on: May 4, 2012
Recombinant single-chain variable fragment-based immunoassay for the authentication of Vietnamese ginseng via
Jiranan Chaingam1, Poomraphie Nuntawong1, Le Van Huy2,3
1Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Background:
Majonoside R2 (MR2) is an ocotillol-type saponin found at 3 %-5 % (w/w) in Panax vietnamensis that serves as a critical biomarker for authenticating sought-after Vietnamese ginseng varieties, such as Ngoc Linh and Lai Chau. However, widespread adulteration with morphologically similar species has created an urgent need for high-throughput, cost-effective authentication methods beyond chromatographic or deoxyribonucleic acid-based techniques.
Methods:
A single-chain variable fragment (scFv) antibody against MR2 was recombinantly expressed in Escherichia coli, purified, and functionally validated. Using this antibody, an indirect competitive enzyme-linked immunosorbent assays (icELISA) approach was optimized for MR2 quantification in complex herbal matrices. The performance of this novel assay was benchmarked against that of a previously validated method using monoclonal antibody (mAb)-based ELISA and verified using authentic Panax spp. and Randia siamensis samples.
Results And Conclusion:
The scFv-based icELISA demonstrated a detection range of 31.25-1000 ng/mL for MR2, with high reproducibility and accuracy (CV <12.4 %, recovery 90.6 %-116.7 %). The assay was found to reliably distinguish authentic Ngoc Linh and Lai Chau ginsengs from other Panax species with high specificity. Recombinant expression in E. coli enables scalable, animal-free production, facilitating the broader adoption of this icELISA across laboratories equipped with standard molecular biology infrastructure. These findings support the integration of scFv-based assays into regulatory frameworks for authenticating Vietnamese ginseng.
