Single-molecule methods, specifically single-molecule counting, convey high sensitivity in research applications. However, single-molecule counting experiments require specialized equipment or consumables to perform. We demonstrate the utility of using bright Streptavidin-Phycoerythrin (SA-PE) conjugates and an epifluorescence microscope, for single-molecule counting applications. In this work, we show that we can visualize single-molecules on glass surfaces, perform single-molecule diagnostic assays on magnetic microparticles, and image individual foci on cell surfaces. This approach is simple and effective for researchers interested in single-molecule counting.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.ab.2022.114955 | DOI Listing |
J Phys Chem A
December 2024
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.
Time-resolved single molecule localization microscopy (TR-SMLM) with a 2 × 2 pixel fiber optic array camera was combined with time-correlated single photon counting (TCSPC) to obtain super-resolved fluorescence lifetime images of individual Cy3 dye molecules and individual colloidal CdSe/CdS/ZnS core/shell/shell semiconductor quantum dots (QDs). The characteristic blinking and bleaching behavior of the Cy3 and the blinking behavior of the QD emitters were used as distinguishing optical characteristics to isolate them and determine their centroid locations with spatial resolution below the optical diffraction limit. TCSPC was used to characterize the fluorescence lifetime and intensity corresponding to each emitter location.
View Article and Find Full Text PDFAnal Bioanal Chem
December 2024
Bio-Metrology Group, Korea Research Institute of Standards and Science, Daejeon, Republic of Korea.
The mole, the SI unit for measuring the amount of a substance, was redefined as a fixed number of entities. This definition enables straightforward quantification of substances by counting individual entities. Counting proves particularly effective for quantifying large and discrete biological entities such as DNA, proteins, viruses, and cells, which are challenging to quantify via traditional physical or chemical methods.
View Article and Find Full Text PDFACS Nano
December 2024
State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China.
The development of novel detection technology for meat species authenticity is imperative. Here, we developed a machine learning-supported, dual-channel biosensor-in-microdroplet platform for meat species authenticity detection named CC-drop (RISPR/Cas12a digital single-molecule microdroplet biosensor). This strategy allowed us to quickly identify and analyze animal-derived components in foods.
View Article and Find Full Text PDFAnal Chem
December 2024
School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
N6-methyladenosine (m6A) demethylase is essential for enzymatically removing methyl groups from m6A modifications and is significantly implicated in the pathogenesis and advancement of various cancers, which makes it a promising biomarker for cancer detection and research. As a proof of concept, we select the fat mass and obesity-associated protein (FTO) as the target m6A demethylase and develop a dandelion-like nanoprobe-based sensing platform by employing biobar-code amplification (BCA) for signal amplification. We construct two meticulously designed three-dimensional structures: reporter-loaded gold nanoparticles (Reporter@Au NPs) and substrate-loaded magnetic microparticles (Substrate@MMPs), which can self-assemble to form dandelion-like nanoprobes via complementary base pairing.
View Article and Find Full Text PDFNano Lett
December 2024
Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong 518060, People's Republic of China.
The primary challenge in microarray-based biological analysis lies in achieving the sensitive and specific detection of single-molecule targets while ensuring high reproducibility. A user-friendly digital imaging platform has been developed for the encoded trichromic profiling of circulating microRNAs (miRNAs). This platform replaces the traditional exponential polymerase amplification reaction (EXPAR) conducted on the microliter scale with a system that confines the amplification process within thousands of femtoliter-sized microdroplet reactors, cross-linked from tetra-armed poly(ethylene glycol) acrylate (Tetra-PEGA) and poly(ethylene glycol) dithiol (HS-PEG-SH), thus offering significant advantages, including minimal sample input, enhanced reactivity, and simplified analytical procedures.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!