We have applied a simple and reliable procedure for imaging biomolecules with the scanning tunneling microscope (STM). The biomolecules are adsorbed on glow-discharged mica, then coated with a thin film of platinum-carbon. We have tested this method with linear and circular (plasmid) DNA molecules. The contrast and resolution of the STM images are comparable to electron micrographs of the same molecules when shadowed. Though the present lateral resolution (5-6 nm) is limited by the grain size of the conductive film, some details like supercoiled regions in the DNA are resolved. This method is interesting for two reasons. First, as an alternative technique for imaging biomolecules. Second, for use as a control in STM studies of bare biomolecules.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0304-3991(92)90431-i | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Capturing the micro-communities: Insights into biogenesis and architecture of bacterial biofilms.
BBA Adv
December 2024
Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, NH 65, Nagaur Road, Karwar, Rajasthan 342037, India.
Biofilm is an assemblage of microorganisms embedded within the extracellular matrix that provides mechanical stability, nutrient absorption, antimicrobial resistance, cell-cell interactions, and defence against host immune system. Various biomolecules such as lipids, carbohydrates, protein polymers (amyloid), and eDNA are present in the matrix playing significant role in determining the distinctive properties of biofilm. The formation of biofilms contributes to resistance against antimicrobial therapy in most of the human infections and exacerbates existing diseases.
View Article and Find Full Text PDFOn-Chip Stimulated Raman Scattering Imaging and Quantification of Molecular Diffusion in Aqueous Microfluidics.
Anal Chem
January 2025
State Key Laboratory of Surface Physics and Department of Physics, Academy for Engineering and Technology, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Shanghai Key Laboratory of Metasurfaces for Light Manipulation, Fudan University, Shanghai 200433, China.
Numerous chemical reactions and most life processes occur in aqueous solutions, where the physical diffusion of small molecules plays a vital role, including solvent water molecules, solute biomolecules, and ions. Conventional methods of measuring diffusion coefficients are often limited by technical complexity, large sample consumption, or significant time cost. Here, we present an optical imaging method to study molecular diffusion by combining stimulated Raman scattering (SRS) microscopy with microfluidics: a "Y"-shaped microfluidic channel forming two laminar flows with a stable concentration gradient across the interface.
View Article and Find Full Text PDFRapid fabrication and dissolution of pressed Ni/Mg matrix targets for Co production.
EJNMMI Radiopharm Chem
January 2025
Department of Nuclear Medicine and Medical Physics, Karolinska University Hospital, Stockholm, 171 76, Sweden.
Background: Beyond the use of conventional short-lived PET radionuclides, there is a growing interest in tracking larger biomolecules and exploring radiotheranostic applications. One promising option for imaging medium-sized molecules and peptides is ⁵⁵Co (T₁/₂ = 17.5 h, β⁺ = 76%), which enables imaging of new and already established tracers with blood circulation of several hours.
View Article and Find Full Text PDFUncommon metastatic journey: unusual breast metastases of medullary thyroid carcinoma: a case report.
BMC Womens Health
January 2025
Department of Surgical Oncology, Salah Azaiez Institute, Faculty of Medicine of Tunis, University of Tunis El Manar, Boulevad 9 Avril Bab Saadoun 1006, Tunis, Tunisia.
Medullary thyroid carcinoma is a neuroendocrine tumor derived from thyroid C-cells. It is a rare aggressive tumor, known to metastasize to lymph nodes, liver, bones, and lungs. We report a case of a young patient with a family history of breast cancer, who developed breast metastases six months post-treatment for medullary thyroid carcinoma.
View Article and Find Full Text PDFTryptophan-specific modification and diversification of peptides and proteins.
Org Biomol Chem
January 2025
Department of Chemistry, Muragachha Government College, Nadia 741154, West Bengal, India.
In spite of being the second-lowest abundant proteinogenic amino acid, approximately 90% of proteins contain at least one tryptophan residue. Hence, the chemoselective functionalization of tryptophan residue can provide access to site-selective bioconjugation of almost all known proteins. With the increase in the utility of bioconjugated proteins and peptides as drugs and therapeutic agents, the development of smart protocols to fabricate and modulate biomolecules has flourished.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!