• Proceedings of the KIEE Conference
• /
• 1998.07g
• /
• pp.2556-2558
• /
• 1998

2-D microwell arrays for micro ELISA (Enzyme-Linked Immuno Solvent Assay) system were fabricated using micromachining technology. The materials for the bottom plate, top plate and sidewall of the microwell were used a #7740 glass, gold and silicon respectively considering bio-compatibility and easy fabrication. Cylindrical or groove shape microwells, which have about $100{\mu}m$ depth and $50{\sim}500{\mu}m$ diameter or width, were arrayed. The fabricated microwell array can be applied to the essential part of a biochip when surface modification is made to immobilize cells or biomolecules on the microwell bottom.

• Biomedical Science Letters
• /
• v.30 no.3
• /
• pp.131-136
• /
• 2024

In this investigation, a novel design for a well-plate structure was created to optimize antigen-antibody reactions. The main objective during the development process was to enhance the internal structure of the well plate and increase the surface area. To improve efficiency, the newly designed well-plate was conical in shape and featured internal protrusions, or fins, which increased the surface area per unit volume by 1.45 times compared to standard plates. The performance of the newly developed well plate was assessed using a sandwich CLEIA system, which demonstrated a detection limit approximately 2.5 times better than that of commercial products. Additionally, the coefficient of variation (CV%) was superior to that of commercial products, with inter-assay CV(%) ≤ 11 and intra-assay CV(%) ≤ 9, compared with inter-assay CV(%) ≤ 15 and intra-assay CV(%) ≤ 10 for commercial products. Furthermore, the newly designed well plate demonstrated higher reaction efficiency, even with smaller sample volumes (25~50 µL) compared to the 50~100 µL typically required by commercial well plates. The incorporation of fine patterns increases the number of active sites available for interaction with the samples, thereby significantly enhancing the reaction sensitivity and overall performance.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.11
• /
• pp.1559-1565
• /
• 2014

Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a $200{\mu}l$ total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at $100^{\circ}C$ for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass.

• Journal of Food Hygiene and Safety
• /
• v.11 no.4
• /
• pp.287-290
• /
• 1996

To control the maximum residue level (MRL) for sulfamethazine (SMZ) residues in pork tissue, a microbial inhibition method is a regulatory screening assay method in Korea. Microwell plate-based competitive enzyme immunoassay (ELISA) kit is avalable for routine screening of SMZ residues in pork tissue. One ELISA kit is evaluated. Phosphate buffer extracts of samples fortified with SMZ at 0, 1, 5, and 10 ng/g were used in a recovery test of the kit. Market pork samples were assayed by the kit. Recovery of sulfamethazine was 104% at 10 ng/g. Intraassay variations and interassay variations for the kit were 7.70% and 5.76%, respectively. Concentration causing 50% inhibition of color development compared with blanks was 16.4ng. The violative pork samples with over MRL (0.1 $\mu\textrm{g}$/g) was 4 of 32 cases (12.5%) by used ELISA kit. This result indicates a possibility of the ELISA kit for screening test of SMZ residues in pork tissue, and still needs a comfirmatory assay for mandatory purposes.

• Journal of Periodontal and Implant Science
• /
• v.30 no.1
• /
• pp.51-65
• /
• 2000

Extracellular matrix component is degraded by enzymes of thematrix metalloproteinases(MMPs). MMPs are produced by both hemopoietic and structural cells. Increased activity of MMP-3 in periodontium is strongly associated with inflammatory periodontal disease. The purpose of the present study was to estimate the effect of BMP-7 on regeneration of periodontium. The optical density was measured by microwell plate reader at 450 nm.The difference of the optical density and the relative activity ofMMP-3 according to the concentration were statistically analyzed by one way ANOVA. The results were as follows: 1. Tetracycline-HCl showed the tendency to inhibit the activity of MMP-3 at the concentration lower than $25{\mu}g/ml$. 2. Doxycycline-HCl inhibited significantly the activity of MMP-3 at the concentration lower than $100{\mu}g/ml$. 3 . Minocycline-HCl inhibited the activity of MMP-3 at the concentration in the range of 10 to 200${\mu}g/ml$. Within the limit of the present study, the above results suggested that bone morphogenetic protein-7 may play a important role in development of periodontium.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.677-693
• /
• 1999

Extracellular matrix component is degraded by enzymes of thematrix metalloproteinases(MMPs). MMPs are produced by both hemopoietic and structural cells. Increased activity of MMP-3 in periodontium is strongly associated with inflammatory periodontal disease. The purpose of the present study was to determine the effect of tetracycline analogues on the activity of MMP-3. Tetracycline-HCl, doxycycline-HCl, and minocycline-HCl were applied to huamn gingival fibroblasts at various concentrations of 10, 25, 50, 100, 200${\mu}g$/ml, and 1 hour later IL-$1{\beta}$ of 25ng/ml was added. After incubation for 24 hours the cells were reacted by enzyme-linked immunosorbent assay using proMMP-3 ELISA kit. The optical density was measured by microwell plate reader at 450nm. The relative activity of MMP-3 was calculated as the percentage of the optical density of each experimental group to that of the control. The difference of the optical density and the relative activity of MMP-3 between the experimental groups and the control wasstatistically analyzed by one way ANOVA. The results were as follows: 1. Tetracycline-HCl showed the tendency to inhibit the activity of MMP-3 at the concentration lower than 25${\mu}g$/ml, but increased significantly the activity of MMP-3 at the concentration of 200${\mu}g$/ml(p<0.05). 2. Doxycycline-HCl inhibited significantly the activity of MMP-3 at the concentration lower than 100${\mu}g$/ml, but increased significantly the activity of MMP-3 at the concentration of 200${\mu}g$/ml(p<0.05). 3. Minocycline-HCl inhibited the activity of MMP-3 at the concentration in the range of 10 to 200${\mu}g$/ml. Within the limit of the present study, the above results suggested that the low concentration of tetracycline analogues could inhibit the activity of MMP-3 induced by IL-$1{\beta}$ in human gingival fibroblasts.