Wednesday, June 13, 2007 4:35:57 PM
Dutch researchers have overcome the traditional incompatibility of Raman microscopy with fluorescence microscopy by exploiting the optical properties of semiconductor fluorescent quantum dots (QDs). They have now used their hybrid Raman fluorescence spectral imaging approach in single-cell microscopy applications.
Biophysical engineers Henk-Jan van Manen and Cees Otto of the University of Twente, The Netherlands, have used fluorescent nanoparticles to broaden the scope of single-cell microscopy by combining it with intracellular chemical analysis based on Raman.
According to the researchers, the need for fluorescent nanoparticles, or quantum dots, arises because common fluorescent labels overshadow the intrinsically weak Raman signals from DNA, proteins and lipids in cells. To side-step this problem, the team used fluorescent quantum dots that emit light in a wavelength region that is well-separated from Raman signals.
The group at the University of Twente has pioneered the use of Raman spectroscopy in investigating the chemical make-up of single cells. Van Manen and Otto have now demonstrated successfully the hybrid technique by illuminating white blood cells under UV at 413 nm, and observing the Raman signal from an enzyme critical to the innate immune response. This allowed them to detect and visualize the enzyme across the cell. In a second proof of principle experiment, the team used 647 nm light to investigate cellular proteins and lipids.
Van Manen and Otto say that the fluorescence Raman microscopy combination provides exciting new possibilities because the nanoparticles coated with antibodies raised against cancer biomarkers could be used to guide Raman microscopy to certain areas in tissues and allow the spread of cancer in a patient to be detected with molecular precision.
"We have exploited the optical properties of nanosized quantum dots to develop two new strategies for combining confocal Raman microscopy with confocal fluorescence microscopy on QD-labelled biological cells," conclude the researchers. The first approach uses resonant Raman microspectroscopy and imaging of enzymes, in this case flavocytochrome b558, and is, the team says, fully compatible with linear fluorescence microscopy of intracellular QDs.
The second method involves continuous-wave two-photon-excited fluorescence of the QDs in white blood cells and does not interfere with non-resonant Raman signals produced by proteins or lipids in the cells. "As these hybrid Raman fluorescence strategies should be applicable to any cell type that is amenable to labelling with QDs," the researchers add, "we envision that hybrid Raman fluorescence microscopy will offer new prospects for integrating QD imaging on cells with spatially resolved, detailed intracellular chemical analysis by broadband Raman microspectroscopy."
Infrared and Raman vibrational spectroscopies reveal the palette of frescos found in the medieval monastery of Karaach Teke
Annali di Chimica, 2007, 97, 491-503
T. Zorba, K.S. Andrikopoulos, K.M. Paraskevopoulos, E. Pavlidou, K. Popkonstantinov, R. Kostova, V. Platnyov, Sister Daniilia
//////////////////////////////////////////////////////////////
Abstract: Vibrational spectroscopy is applied on samples obtained from the excavation area of the medieval Monastery (10th century) of Karaach-Teke in Bulgaria. The results of the corresponding study, reveal the type of materials used for the creation of the wall-paintings and give evidence of Byzantine influence, a fact that further supports the well known impact of Byzantium on the technology and thematic-aesthetic features of iconography in Bulgaria during this era. In addition, the complementarity of FTIR and µ-Raman spectroscopies in the identification of pigments is indicated.
NOTE Vibrational=resonant. (I think) Alla this may be a bit beyond my pay grade...but may be of interest,,
Ole Crowe
Recent IVAC News
- Intevac to Announce Third Quarter 2024 Results on November 11th • Business Wire • 10/14/2024 01:00:00 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 10/01/2024 08:06:01 PM
- Intevac Announces Appointment of Kevin Barber as Board Chairman • Business Wire • 10/01/2024 08:05:00 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 08/29/2024 03:33:30 PM
- Form 3 - Initial statement of beneficial ownership of securities • Edgar (US Regulatory) • 08/28/2024 07:35:37 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 08/27/2024 08:05:54 PM
- Intevac Welcomes Eiji Miyanaga to its Board of Directors • Business Wire • 08/27/2024 08:05:00 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 08/16/2024 03:55:08 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 08/16/2024 03:48:33 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 08/16/2024 03:38:36 PM
- Intevac Reports Inducement Grants under Nasdaq Listing Rule 5635(c)(4) • Business Wire • 08/15/2024 10:30:00 PM
- Form S-8 - Securities to be offered to employees in employee benefit plans • Edgar (US Regulatory) • 08/06/2024 08:41:06 PM
- Form 10-Q - Quarterly report [Sections 13 or 15(d)] • Edgar (US Regulatory) • 08/06/2024 08:06:24 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 08/05/2024 08:06:00 PM
- Intevac Announces Second Quarter 2024 Financial Results • Business Wire • 08/05/2024 08:05:00 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 08/01/2024 02:04:10 PM
- Intevac to Announce Second Quarter 2024 Results on August 5th • Business Wire • 07/15/2024 01:00:00 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 07/11/2024 02:44:33 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 07/10/2024 01:05:31 PM
- Intevac Appoints Cameron McAulay as Chief Financial Officer • Business Wire • 07/10/2024 01:00:00 PM
- Form SD - Specialized disclosure report • Edgar (US Regulatory) • 05/17/2024 08:10:58 PM
- Form 8-K - Current report • Edgar (US Regulatory) • 05/17/2024 08:06:06 PM
- Form 4 - Statement of changes in beneficial ownership of securities • Edgar (US Regulatory) • 05/17/2024 01:26:34 PM
SANUWAVE Announces Reverse Stock Split, Note and Warrant Exchange, and PIPE Offering • SNWV • Oct 18, 2024 9:31 AM
Vocodia Addresses Recent Stock Price Movement and Future Strategic Partnerships • VHAI • Oct 18, 2024 9:00 AM
Mass Megawatts Announces the Start of an Online Discount Solar Energy Equipment Business with Revenue Recognized for the First Time Since Year 2010 in this Fiscal Quarter • MMMW • Oct 18, 2024 7:32 AM
Unitronix Corp Advances DeFi Innovation with Tokenized Real-World Assets Integration • UTRX • Oct 17, 2024 7:38 AM
Mass Megawatts Commences Solar Energy Sales Efforts • MMMW • Oct 16, 2024 7:45 AM
SANUWAVE Health Announces 1-For-375 Reverse Stock Split • SNWV • Oct 16, 2024 7:40 AM