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Laurdan

Laurdan is a fluorescent probe used to study membrane properties and lipid organization.
It exhibits a blue-to-green shift in its emission spectrum in response to changes in membrane fluidity and polarity.
Laurdan research is crucial for understanding cellular membranes and their role in biological processes.
PubCompare.ai is an AI-driven platform that can enhance the reproducibility of Laurdan research by helping researchers easily locate relevant protocols from literature, preprints, and patents, while utilizing AI-driven comparisons to identify the best protocols and products.
This streamlines the research workflow and optimizes Laurdan studies.

Most cited protocols related to «Laurdan»

1
Confocal Microscopy of Membrane Samples
Cited 14 times
Spectral imaging of the different membrane samples was performed on a Zeiss LSM 780 confocal microscope equipped with a 32-channel GaAsP detector array. Laser light at 405 and 488 nm was selected for fluorescence excitation of C-Laurdan and Di-4-ANEPPDHQ, respectively. The lambda detection range was set between 415 and 691 nm for C-Laurdan, and between 495 and 691 nm for Di-4-ANEPPDHQ (Figure S1). The wavelengths 415 and 691 nm were the ultimate limits of our detector. Despite the fact that wavelength intervals of down to 4 nm could be chosen for the individual detection channels, we have set these intervals to 8.9 nm, which allowed the simultaneous coverage of the whole spectrum with the 32 detection channels (Figure S1). The images were saved in .lsm file format and then analyzed by using a custom plug-in compatible with Fiji/ImageJ, as described further on.
Sezgin E., Waithe D., Bernardino de la Serna J, & Eggeling C. (2015). Spectral Imaging to Measure Heterogeneity in Membrane Lipid Packing. Chemphyschem, 16(7), 1387-1394.
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Publication 2015
di-4-ANEPPDHQ Fluorescence laurdan Light Microscopy, Confocal Tissue, Membrane
2
Multimodal Microscopy of Membrane Lipid Order
Cited 7 times
Images were obtained with a microscope (DM IRE2; Leica) equipped with photon-multiplier tubes and acquisition software (Leica). Laurdan fluorescence was excited at 800 nm with a multiphoton laser system (Verdi/Mira 900; Coherent). Laurdan intensity images were recorded simultaneously and emissions were in the range of 400–460 and 470–530 nm (Gaus et al., 2003 (link)). Microscopy calibrations were performed as described previously (Gaus et al., 2003 (link)). For confocal microscopy a helium-neon laser was used to excite Cy3 (Ex: 543 nm; Em: 550–620 nm) and Cy5 (Ex: 633 nm; Em 650–720 nm) with appropriate cut-off filters and pinhole widths. For fixed cells, a 100× oil objective, NA 1.4, was used; for live cell, a 63× water objective, NA 1.3, was used, and images were recorded at RT.
Gaus K., Le Lay S., Balasubramanian N, & Schwartz M.A. (2006). Integrin-mediated adhesion regulates membrane order. The Journal of Cell Biology, 174(5), 725-734.
Publication 2006
Cells Fluorescence Helium Neon Gas Lasers laurdan Microscopy Microscopy, Confocal
3
Antibiotics Mode of Action in Bacillus
Cited 6 times
Details on antibiotics, bacterial strains, and experimental procedures can be found in Text S2 in the supplemental material. A list of B. subtilis strains used in this study is displayed in Table S1. All strains were grown at 30°C under steady agitation in Luria-Bertani broth (LB). MICs were determined in a standard serial dilution assay. Growth experiments were carried out in 96-well format in a temperature-controlled BioTek Synergy MX plate reader under continuous shaking. All mode-of-action assays were performed with log-phase B. subtilis cells at an OD at 600 nm (OD600) of 0.3 at 30°C under steady agitation. Unless otherwise noted, cells were treated with 1× MIC of the respective antibiotics for 10 min. Fluorescence microscopy and staining of cells with fluorescent dyes were carried out as described previously (44 (link), 60 (link), 98 (link)). Electron microscopy was performed using a recently described flat embedding technique (60 (link)). The membrane potential was measured with DiSC(3)5 as described by Te Winkel et al. (98 (link)). Propidium iodide influx and laurdan spectroscopic assays were essentially performed as described by Müller et al. (44 (link)). Electrophysiological and NMR measurements were performed in 3:1 POPG-POPE or pure POPE, respectively, as described in Text S2. Time-lapse microscopy and SIM were essentially performed as described by Saeloh et al. (60 (link)). Activity against stationary-phase cells was determined using overnight cultures of B. subtilis and S. aureus. Antibiotic concentrations were adjusted to the higher cell count, and cells were incubated with antibiotics for 9 h prior to CFU determination.
Wenzel M., Rautenbach M., Vosloo J.A., Siersma T., Aisenbrey C.H., Zaitseva E., Laubscher W.E., van Rensburg W., Behrends J.C., Bechinger B, & Hamoen L.W. (2018). The Multifaceted Antibacterial Mechanisms of the Pioneering Peptide Antibiotics Tyrocidine and Gramicidin S. mBio, 9(5), e00802-18.
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Publication 2018
1-palmitoyl-2-oleoylglycero-3-phosphoglycerol 1-palmitoyl-2-oleoylphosphatidylethanolamine Antibiotics Antibiotics, Antitubercular Bacteria Biological Assay Cells Complement factor H Electron Microscopy Fluorescent Dyes laurdan Membrane Potentials Microscopy Microscopy, Fluorescence Propidium Iodide Spectrum Analysis Staphylococcus aureus Strains Technique, Dilution
4
Fluorescence Spectral Imaging Analysis
Cited 5 times

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Publication 2016
Fluorescence laurdan Mass Spectrometry Radius
5
Liposome Characterization via C-Laurdan Spectroscopy
Cited 4 times
Liposomes were created, and C-laurdan spectroscopy was performed as previously described in Kaiser et al. (2009) (link). For liposomes, lipids in chloroform/MeOH were dried under vacuum and recovered in HBS (10 mM Hepes, 150 mM NaCl, and 0.2 mM EDTA, pH 7.25) at 68°C. After 10 freeze-thaw cycles, liposomes were extruded at 70°C using 100-nm polyvinylidene fluoride membranes. Liposome, cellular, and virus membrane amounts were standardized via scattering fluorescence emission at 425 nm (λex = 385 nm) to 30,000 intensity units stained with 100 µM C-laurdan for 15 min at room temperature. C-laurdan was then excited at 385 nm. The GP value was calculated from the following emission bands: Ch1 (400–460 nm) and Ch2 (470–530 nm). GP = (ICh1 − ICh2)/(ICh1 + ICh2), in which I is the fluorescence intensity, from spectra at a 1-nm resolution recorded on a fluorescence spectrometer (FluoroMax-3; Horiba) with a thermostat (SC 100-A5B; Thermo Fisher Scientific) at 23°C.
Gerl M.J., Sampaio J.L., Urban S., Kalvodova L., Verbavatz J.M., Binnington B., Lindemann D., Lingwood C.A., Shevchenko A., Schroeder C, & Simons K. (2012). Quantitative analysis of the lipidomes of the influenza virus envelope and MDCK cell apical membrane. The Journal of Cell Biology, 196(2), 213-221.
Publication 2012
CASP2 protein, human Cells Chloroform Edetic Acid Fluorescence Freezing HEPES laurdan Lipids Liposomes polyvinylidene fluoride Sodium Chloride Spectrum Analysis Tissue, Membrane Vacuum Virus

Most recents protocols related to «Laurdan»

1
Laurdan Fluorescence Spectroscopy and Microscopy
Not available on PMC !
Laurdan was dissolved in DMSO at a concentration of 1 mM as a stock solution. To measure the steadystate Laurdan uorescence spectrum in cell membrane, HepG-2 and NP-8 cells were seeded in 6-well plates. After 24 h treatments with different liposomes or free 2-OHOA ( rstly dissolved in DMSO at a concentration of 20 mM as stock solution, then diluted in cell culture media for cell treatment), the culture media was carefully removed, and the cells were gently washed with D-PBS. Subsequently, fresh preheated media containing 10 µM Laurdan was introduced into the wells and incubated for 30 minutes in a cell culture incubator shielded from light. Following Laurdan staining, cells were washed and detached using trypsin. The collected cells were suspended in D-PBS and analyzed using a uorescence spectrometer (FP-8500, Jasco, Japan). Steady-state Laurdan spectra were obtained with an excitation wavelength of 345 nm, and emission was collected in the range of 400-600 nm.
The Laurdan steady-state uorescence spectra data from uorescence spectrometer were collected and analyzed. The value (GP value calculated according to steady-state Laurdan spectra) was calculated according to the Eq. ( 2):
2
Where and represent the uorescence intensity at 440 and 490 nm, respectively.
For two-photon microscopy observations, cells were initially cultured in 35 mm Φ glass-bottom dishes.
Laurdan staining was performed as previously described. Following staining, the samples were observed under a two-photon microscopy. To maintain the temperature and CO 2 concentration of the cell samples during microscopy observation, the glass bottom dishes were placed in a living cell imaging chamber equipped with a stage-top incubator (INUB-PPZI, Tokai Hit, Japan) to sustain a 37℃ and 5% CO 2 environment. Two-photon uorescence images of the Laurdan-labeled cells were obtained with an inverted microscopes (Eclipse TE2000-U, Nikon, Japan) with a ×60 water-immersion objective (Plan Apo VC 60×, NA = 1.2, Nikon, Japan). A Ti-sapphire laser (Chameleon Vision II, Coherent, USA) with a repetition rate of 80 MHz and pulse width of 140 femtosecond (fs) was used as the excitation laser. The wavelength peak was tuned to 780 nm and the power was adjusted to 100 mW. The group delay dispersion (GDD) was adjusted to 14,000 femtosecond squared (fs 2 ). Laurdan emission from the cell samples were ltered through 436/20 nm (blue) and 495/25 nm (cyan) bandpass lters. The uorescence intensity of two channels were detected using a laser-scanning uorescence detector (D-Eclipse C1, Nikon, Japan). The relative sensitivities of the two channels were determined using 0.1 mM Laurdan in DMSO, and the calibration factor (G-factor) was calculated (refer to supplementary information). Two-photon microscopy images of Laurdan-stained cell membrane were analyzed using the imageJ software. Laurdan GP images were acquired by calculating the GP value of each pixel. The (GP value calculated according to Laurdan two-photon microscopy images) of each pixel, was calculated according Eq. ( 3).
Rui X., Okamoto Y., Fukushima S., Watanabe N., & Umakoshi H. (2024). Investigating the impact of 2-OHOA-embedded liposomes on biophysical properties of cancer cell membranes via Laurdan two-photon microscopy imaging.
Publication 2024
2
Measuring Membrane Fluidity in B. subtilis
Kinetic membrane fluidity measurements were performed as described previously (48 (link)) with minor modifications. B. subtilis 168CA was grown in medium containing 0.2% glucose. After reaching an OD600 of 0.6, cells were stained with 10-µM Laurdan (AnaSpec) for 5 min, washed in Laurdan buffer [phosphate-buffered saline, 0.2% glucose, 1% dimethylformamide (DMF)], and resuspended in the same buffer to an OD600 of 0.8. A DMF concentration of 1% was constantly maintained to prevent precipitation of the dye. Sample aliquots of 100 µL were added to 96-well black polystyrene microplates (Corning), and fluorescence was measured at an excitation wavelength of 350 nm and emission wavelengths of 460 nm and 500 nm with 15 nm bandwidth each. After recording the baseline for 5 min, 100 µL of prewarmed Laurdan buffer containing the respective antibiotics was added and measurements were continued for another 30 min. Cells grown in KCl-MHB were washed and resuspended in Laurdan buffer containing 300-mM KCl. General polarization values of Laurdan were calculated according to Wenzel et al. (48 (link)).
Schäfer A.B., Sidarta M., Abdelmesseh Nekhala I., Marinho Righetto G., Arshad A, & Wenzel M. (2024). Dissecting antibiotic effects on the cell envelope using bacterial cytological profiling: a phenotypic analysis starter kit. Microbiology Spectrum, 12(3), e03275-23.
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Publication 2024
3
Membrane Fluidity Measurement of Bacteria
The membrane general polarization (GP) was measured using the Laurdan (1-[6-(Dimethylamino) naphthalen-2-yl] dodecan-1-one) (ThermoFisher, Rockford, IL, USA). Briefly, bacteria were incubated overnight on TSA. Bacteria were diluted 1:100 and grown up to a A600 of 0.4. Afterwards, 10 µM Laurdan was added for 10 min. Bacteria were washed 4 times in preheated microtubes. Bacteria were then exposed to either TM-02 or TM-03 at various concentrations. Images were taken on a Zeiss observer Z1 with an excitation wavelength of 350 nm and emission of 440 nm and 520 nm. The images were analyzed using ImageJ and GP was calculated using this formula [16 (link)]:
Langlois J.P., Larose A., Brouillette E., Delbrouck J.A., Boudreault P.L, & Malouin F. (2024). Mode of Antibacterial Action of Tomatidine C3-Diastereoisomers. Molecules, 29(2), 343.
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Publication 2024
4
Laurdan-Labeled LUVs Membrane Packing
The stock suspension of 100 μM LUV100 was labeled with 0.2 μM concentration of 2-dimethylamino-6-lauroyl naphthalene (Laurdan, Molecular Probes, dissolved in dimethylsulfoxide, DMSO) at 37 °C for 60 min, the final ratio of Laurdan per lipid was 1 : 500. Final concentration of DMSO was 0.2% in all samples. The LUV suspension was split to individual aliquots of 0.1 mL. To study the possible shift in packing of the lipids in membranes with two different compositions (DOPE : DOPG and DOPG : DOPE, 2 : 1, w/w), we measured the generalized polarization (GP) of Laurdan-labeled LUVs under stable temperature 27 °C using FluoroMax-3 spectrofluorometer (Jobin Yvon, Horiba). Fluorescence spectra were measured from 400 to 600 nm (after excitation at 365 nm), with 4 nm bandpass. GP values were calculated according to Parasassi et al. (1990).28 (link)
Dugić M., Brzobohatá H., Mojr V., Dolejšová T., Lišková P., Do Pham D.D., Rejman D., Mikušová G, & Fišer R. (2024). LEGO-lipophosphonoxins: length of hydrophobic module affects permeabilizing activity in target membranes of different phospholipid composition. RSC Advances, 14(4), 2745-2756.
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Publication 2024
5
C-Laurdan Imaging for Membrane Fluidity
C-Laurdan imaging was performed as previously described 98 (link)–102 (link). Briefly, cells were washed with PBS and stained with 10 µg/mL C-Laurdan for 10 min on ice, then imaged using confocal microscopy on a Leica SP8 with spectral imaging at 60× (water immersion, NA= X) and excitation at 405 nm. The emission was collected as two images: 420–460 nm and 470–510 nm. MATLAB (MathWorks, Natick, MA) was used to calculate the two-dimensional (2D) GP map, where GP for each pixel was calculated as previously described 102 (link). Briefly, each image was background subtracted and thresholded to keep only pixels with intensities greater than 3 standard deviations of the background value in both channels. The GP image was calculated for each pixel using Eq.1. GP maps (pixels represented by GP value rather than intensity) were imported into ImageJ. To calculate the average PM GP, line scans drawn across individual cells. PM GP values were taken as peak GP values from the periphery of the cell, whereas internal membranes were calculated as the average of all values outside the PM peak. The average GP of the internal membranes was calculated by determining the average GP of all pixels in a mask drawn on each cell just inside of the PM.
Henry W.S., Müller S., Yang J.S., Innes-Gold S., Das S., Reinhardt F., Sigmund K., Phadnis V.V., Wan Z., Eaton E., Sampaio J.L., Bell G.W., Viravalli A., Hammond P.T., Kamm R.D., Cohen A.E., Boehnke N., Hsu V.W., Levental K.R., Rodriguez R, & Weinberg R.A. (2024). Ether lipids influence cancer cell fate by modulating iron uptake. bioRxiv.
Publication Preprint 2024

Top products related to «Laurdan»

1
Laurdan by Thermo Fisher Scientific
Sourced in United States
Laurdan is a fluorescent probe used in the analysis of membrane properties and dynamics. It is a lipid-soluble dye that exhibits a shift in its emission spectrum in response to changes in the polarity and packing of the surrounding lipid environment. Laurdan is a useful tool for studying the phase behavior and physical properties of lipid membranes.
2
Laurdan by Merck Group
Sourced in United States, Germany, France
Laurdan is a fluorescent probe used in research applications. It is a sensitive environment-sensitive dye that can provide information about the polarity and fluidity of lipid membranes and other biological systems.
3
6 dodecanoyl 2 dimethylaminonaphthalene laurdan by Thermo Fisher Scientific
Sourced in United States
6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) is a fluorescent dye used in various biochemical and biophysical applications. It is a lipophilic probe that exhibits solvent-dependent fluorescence properties, making it useful for studying membrane properties and dynamics.
4
1 palmitoyl 2 oleoyl sn glycero 3 phosphocholine by Avanti Polar Lipids
Sourced in United States
1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine is a phospholipid consisting of a glycerol backbone with a palmitic acid and an oleic acid esterified to the first and second carbons, respectively, and a phosphocholine group attached to the third carbon. This compound is a commonly used lipid in various biochemical and biophysical applications.
5
Laurdan dye by Thermo Fisher Scientific
Laurdan dye is a fluorescent probe used for the study of lipid membranes and their properties. It exhibits an emission wavelength shift in response to changes in the polarity of its local environment, making it a useful tool for monitoring membrane fluidity and phase transitions.
6
1 6 diphenyl 1 3 5 hexatriene dph by Thermo Fisher Scientific
Sourced in United States
1,6-diphenyl-1,3,5-hexatriene (DPH) is a fluorescent probe used in various applications. It is a rod-like molecule with a polarized structure that exhibits changes in fluorescence characteristics when incorporated into lipid bilayers or other hydrophobic environments.
7
1 2 dioleoyl sn glycero 3 phosphocholine by Avanti Polar Lipids
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1,2-dioleoyl-sn-glycero-3-phosphocholine is a synthetic lipid compound. It is a phospholipid that consists of two oleic acid chains attached to a glycerol backbone, with a phosphocholine headgroup.
8
Dimethyl sulfoxide (dmso) by Merck Group
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DMSO is a versatile organic solvent commonly used in laboratory settings. It has a high boiling point, low viscosity, and the ability to dissolve a wide range of polar and non-polar compounds. DMSO's core function is as a solvent, allowing for the effective dissolution and handling of various chemical substances during research and experimentation.
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Calcein is a fluorescent dye used in various laboratory applications. It functions as a calcium indicator, allowing for the detection and measurement of calcium levels in biological samples.

More about "Laurdan"

Laurdan, a fluorescent probe, is a crucial tool for studying membrane properties and lipid organization.
It undergoes a blue-to-green shift in its emission spectrum in response to changes in membrane fluidity and polarity, making it invaluable for understanding cellular membranes and their role in biological processes.
Researchers can leverage the power of PubCompare.ai, an AI-driven platform, to enhance the reproducibility of their Laurdan research.
This platform allows users to easily locate relevant protocols from literature, preprints, and patents, while utilizing AI-driven comparisons to identify the best protocols and products.
This streamlines the research workflow and optimizes Laurdan studies.
In addition to Laurdan, related probes such as 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1,6-diphenyl-1,3,5-hexatriene (DPH) are also used to investigate membrane properties.
Solvents like DMSO and lipids such as 1,2-dioleoyl-sn-glycero-3-phosphocholine and Cholesterol are commonly used in Laurdan-based experiments.
By harnessing the insights and tools provided by PubCompare.ai, researchers can streamline their Laurdan research, improve reproducibility, and gain a deeper understanding of cellular membranes and their role in various biological processes.