Western blotting (WB) is widely used in life science studies and clinical diagnoses to detect target proteins in tested samples, such as cells or tissues, via specific antibody–antigen interactions. However, reducing both of the high material consumption costs, such as expensive antibodies, and long operation times, is still necessary to break through the WB efficiency bottleneck, especially in mass detection processes. Intuitively, these two expectations present a dilemma because further reducing the antibody consumption would prolong the operation time and increasing the antibody concentration could decrease the operation time but increase the material costs based on the standard WB protocol. It is important to note an issue that arises in the standard protocol due to the widespread use of highly diluted solutions of primary antibodies (generally between 0.5 and 5 g/mL to reduce material costs): millions of solvent molecules are homogeneously distributed around each solute (antibody) in the dilution process. As a result, a much longer path is formed, preventing the antibodies from contacting and binding to the antigens on the membrane. Moreover, the thicker the solution in the incubation container is, the lower the average contact probability of the antibody on the membrane becomes . This hinders the chemical reaction process and thus requires a much longer incubation time. Theoretically, gentle agitation, for example by an orbital shaker, could help to enhance the contact probability during the chemical reaction, but this would also increase the amount of antibody waste adhered on the walls of the incubation container. Based on this analysis, keeping the membrane area constant and reducing the depth of the probing solution not only shortens the average contact distance of the antibodies to the antigens on the membrane (to enhance the chemical reaction, thus shortening the operation time) but also reduces the material consumption costs (due to the lower solution requirements). A miniaturized coater1 for thin-film direct coating (TDC) has been developed. The m-thin film of highly diluted antibody solution (0.04 g/mL) was then directly and uniformly coated on the tested membrane. This novel TDC technique invented at NTU could markedly reduce the amount of antibody required for WB with an even better signal2. Furthermore, by using the advanced technique of TDC with suction (TDCS) to further enhance the performance, the signal-to-noise ratio of immunoblotting can be further increased, and the amount of antibody consumption can even be reduced by a factor of 100 in comparison with conventional WB. Theoretically, the corresponding operation time can be reduced from 3 hours in conventional WB to approximately 5 minutes or even less using TDCS. This novel device can be applied to the high-throughput screening of antibody-drug targets, functional assays, and cell-based binding assays, as well as technology transfer for industrial commercialization. 1. Wang, A.-B., Hsieh, Y.-W., Liu, Y.-J., Coating Module, TW Patent I 496625, JP Patent 5837003, 2015. 2. Yen, Y.-K., Jiang, Y-W., Chang, S.-C., and Wang, A.–B., Western blotting by thin-film direct coating, Analytical Chemistry, 86, 5164-5170, 2014. 3. Liu, C.-Y., Lu, D.-C., Jiang, Y.-W., Yen, Y.-K., Chang, S.-C., and Wang, A.–B., Easy and Fast Western Blotting by Thin-Film Direct Coating with Suction, Analytical Chemistry, 88 (12), 6349–6356, 2016. Reference 1. An-Bang Wang, Yu-Wen Hsieh, Yu-Ju Liu, Coating Module, TW Patent I 496625, JP Patent 5837003, 2015. 2. Yi-Kuang Yen, Yi-Wei Jiang, Shih- Chung Chang, and An-Bang Wang. (2014). Western blotting by thin-film direct coating, Analytical Chemistry, 86 (10), 5164-5170. DOI: 10.1021/ac5010162 3. Chao-Yuan Liu, De-Chao Lu, Yi- Wei Jiang, Yi-Kuang Yen, Shih- Chung Chang and An-Bang Wang. (2016). Easy and Fast Western Blotting by Thin-Film Direct Coating with Suction, Analytical Chemistry, 88 (12), 6349-6356. DOI: 10.1021/ acs.analchem.6b00699 Professor An-Bang Wang Institute of Applied Mechanics abwang@iam.ntu.edu.tw