We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




High-Resolution Endoscope Reveals Single Cells

By LabMedica International staff writers
Posted on 10 Jan 2012
Print article
Image: Berkeley Lab chemist Peidong Yang, a leading authority on semiconductor nanowires (Photo courtesy of Roy Kaltschmidt, Berkely Lab Public Affairs).
Image: Berkeley Lab chemist Peidong Yang, a leading authority on semiconductor nanowires (Photo courtesy of Roy Kaltschmidt, Berkely Lab Public Affairs).
A versatile and robust nanowire-based optical probe can provide high-resolution images of the interior of a single living cell, or precisely deliver genes, proteins, therapeutic drugs or other cargo without injuring or damaging the cell.

Researchers at the US Lawrence Berkeley National Laboratory (Berkeley, CA, USA) and the University of California (UC Berkeley; USA) created the novel endoscope by attaching a tin oxide nanowire waveguide to the tapered end of an optical fiber. Light travelling along the optical fiber was effectively coupled into the nanowire, where it was reemitted into free space upon reaching the tip. The nanowire tip is extremely flexible, due to its small size and high aspect ratio, yet it can endure repeated bending and buckling so that it can be used multiple times. Another possible application of the system is biosensing and single-cell electrophysiology.

To test the nanowire endoscope as a local light source for subcellular imaging, the researchers optically coupled it to an excitation laser and guided blue light across the membrane and into the interiors of individual HeLa cells, the most commonly used immortalized human cell line for scientific research. Illuminating the intracellular environment of the cells with blue light using the nanoprobe did not harm the cells, since the illumination volume was at the pico-liter scale. Neither did the contact with the cell cytoplasm induce cell death, apoptosis, significant cellular stress, or membrane rupture. The study was published on December 18, 2011, in Nature Nanotechnology.

“By combining the advantages of nanowire waveguides and fiber-optic fluorescence imaging, we can manipulate light at the nanoscale inside living cells for studying biological processes within single living cells with high spatial and temporal resolution,” said lead author chemist Peidong Yang, PhD, of the Berkeley Lab's Materials Sciences Division. “We've shown that our nanowire-based endoscope can also detect optical signals from subcellular regions and, through light-activated mechanisms, can deliver payloads into cells with spatial and temporal specificity.”

Once the biocompatibility of the nanowire endoscope was demonstrated, the researchers tested the device’s capabilities for delivering payloads to specific sites inside a cell. To do so, they attached quantum dots to the tin oxide nanowire tip of the endoscope using photo-activated linkers that can be cleaved by low-power ultraviolet (UV) radiation. Within one minute, the functionalized nanowire endoscope was able to release its quantum dot cargo into targeted intracellular sites.

The directional blue laser light was then used to excite one of two quantum dot clusters that were located only two micrometers apart. With the tight illumination area and small separation between the light source and the dots, low background fluorescence and high imaging contrast were ensured; the photo activation to release the dots had no significant effect on cell viability.

Related Links:
Lawrence Berkeley National Laboratory
University of California


Gold Member
Antipsychotic TDM Assays
Saladax Antipsychotic Assays
Verification Panels for Assay Development & QC
Seroconversion Panels
New
Anti-HHV-6 IgM Assay
anti-HHV-6 IgM ELISA (semiquant.)
New
Toxoplasma Gondii Immunoassay
Toxo IgM AccuBind ELISA Kit

Print article

Channels

Clinical Chemistry

view channel
Image: The tiny clay-based materials can be customized for a range of medical applications (Photo courtesy of Angira Roy and Sam O’Keefe)

‘Brilliantly Luminous’ Nanoscale Chemical Tool to Improve Disease Detection

Thousands of commercially available glowing molecules known as fluorophores are commonly used in medical imaging, disease detection, biomarker tagging, and chemical analysis. They are also integral in... Read more

Immunology

view channel
Image: The cancer stem cell test can accurately choose more effective treatments (Photo courtesy of University of Cincinnati)

Stem Cell Test Predicts Treatment Outcome for Patients with Platinum-Resistant Ovarian Cancer

Epithelial ovarian cancer frequently responds to chemotherapy initially, but eventually, the tumor develops resistance to the therapy, leading to regrowth. This resistance is partially due to the activation... Read more

Microbiology

view channel
Image: The lab-in-tube assay could improve TB diagnoses in rural or resource-limited areas (Photo courtesy of Kenny Lass/Tulane University)

Handheld Device Delivers Low-Cost TB Results in Less Than One Hour

Tuberculosis (TB) remains the deadliest infectious disease globally, affecting an estimated 10 million people annually. In 2021, about 4.2 million TB cases went undiagnosed or unreported, mainly due to... Read more

Pathology

view channel
Image: The ready-to-use DUB enzyme assay kits accelerate routine DUB activity assays without compromising data quality (Photo courtesy of Adobe Stock)

Sensitive and Specific DUB Enzyme Assay Kits Require Minimal Setup Without Substrate Preparation

Ubiquitination and deubiquitination are two important physiological processes in the ubiquitin-proteasome system, responsible for protein degradation in cells. Deubiquitinating (DUB) enzymes contain around... Read more

Technology

view channel
Image: The HIV-1 self-testing chip will be capable of selectively detecting HIV in whole blood samples (Photo courtesy of Shutterstock)

Disposable Microchip Technology Could Selectively Detect HIV in Whole Blood Samples

As of the end of 2023, approximately 40 million people globally were living with HIV, and around 630,000 individuals died from AIDS-related illnesses that same year. Despite a substantial decline in deaths... Read more

Industry

view channel
Image: The collaboration aims to leverage Oxford Nanopore\'s sequencing platform and Cepheid\'s GeneXpert system to advance the field of sequencing for infectious diseases (Photo courtesy of Cepheid)

Cepheid and Oxford Nanopore Technologies Partner on Advancing Automated Sequencing-Based Solutions

Cepheid (Sunnyvale, CA, USA), a leading molecular diagnostics company, and Oxford Nanopore Technologies (Oxford, UK), the company behind a new generation of sequencing-based molecular analysis technologies,... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.