Name: continuous-wave thulium laser for heating cultured cells to investigate cellular thermal effects
Uploaded: 2017-06-30T13:00:00
Description: Watch this Scientific Journal Video about Continuous-wave Thulium Laser for Heating Cultured Cells to Investigate Cellular Thermal Effects at JoVE.com

This work was supported by a research grant from the German Federal Ministry of Education and Research (BMBF) (grant #13GW0043C) and and a European Office of Aerospace Research and Development (EOARD, grant # FA9550-15-1-0443)

1. RPE Cell Culture
<ol>
	<li>Isolation of RPE cells from porcine eyes
	<ol>
		<li>Obtain freshly enucleated porcine eyes from the local slaughterhouse. Keep them cool (4 &#176;C) and in a dark environment.</li>
		<li>Remove extracellular tissues with scissors and soak the eyes in an antiseptic solution for 5 min.</li>
		<li>Place the eyes in sterilized phosphate-buffered saline without calcium and magnesium (PBS (-)) until use.</li>
		<li>Using a scalpel, penetrate the sclera at about 5 mm posterior t...

     

<ol>
	<li>Inagaki, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+efficacy+of+pure+yellow+(577-nm)+and+810-nm+subthreshold+micropulse+laser+photocoagulation+combined+with+yellow+(561-577-nm)+direct+photocoagulation+for+diabetic+macular+edema.">Comparative efficacy of pure yellow (577-nm) and 810-nm subthreshold micropulse laser photocoagulation combined with yellow (561-577-nm) direct photocoagulation for diabetic macular edema.</a> Jpn J Ophthalmol. 59 (1), 21-28 (2015).</li><li>Roider, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+retina+therapy+(SRT)+for+clinically+significant+diabetic+macular+edema.">Selective retina therapy (SRT) for clinically significant diabetic macular edema.</a> Graefes Arch Clin Exp Ophthalmol. 248 (9), 1263-1272 (2010).</li><li>Brinkmann, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+temperature+determination+during+retinal+photocoagulation+on+patients.">Real-time temperature determination during retinal photocoagulation on patients.</a> J Biomed Opt. 17 (6), 061219 (2012).</li><li>Yoshimura, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photocoagulated+human+retinal+pigment+epithelial+cells+produce+an+inhibitor+of+vascular+endothelial+cell+proliferation.">Photocoagulated human retinal pigment epithelial cells produce an inhibitor of vascular endothelial cell proliferation.</a> Invest Ophthalmol Vis Sci. 36 (8), 1686-1691 (1995).</li><li>Denton, M. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Damage+Thresholds+for+Exposure+to+NIR+and+Blue+Lasers+in+an+In+Vitro+RPE+Cell+System.">Damage Thresholds for Exposure to NIR and Blue Lasers in an In Vitro RPE Cell System.</a> Invest Ophthalmol Vis Sci. 47 (7), 3065-3073 (2006).</li><li>Shrestha, R., Choi, T. Y., Chang, W., Kim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+high-precision+micropipette+sensor+for+cellular-level+real-time+thermal+characterization.">A high-precision micropipette sensor for cellular-level real-time thermal characterization.</a> Sensors (Basel). 11 (9), 8826-8835 (2011).</li><li>Gao, F., Ye, Y., Zhang, Y., Yang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Water+bath+hyperthermia+reduces+stemness+of+colon+cancer+cells.">Water bath hyperthermia reduces stemness of colon cancer cells.</a> Clin Biochem. 46 (16-17), 1747-1750 (2013).</li><li>Jansen, E. D., van Leeuwen, T. G., Motamedi, M., Borst, C., Welch, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperature+dependence+of+the+absorption+coefficient+of+water+for+midinfrared+laser+radiation.">Temperature dependence of the absorption coefficient of water for midinfrared laser radiation.</a> Lasers Surg Med. 14 (3), 258-268 (1994).</li><li>Iwami, H., Pruessner, J., Shiraki, K., Brinkmann, R., Miura, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protective+effect+of+a+laser-induced+sub-lethal+temperature+rise+on+RPE+cells+from+oxidative+stress.">Protective effect of a laser-induced sub-lethal temperature rise on RPE cells from oxidative stress.</a> Exp Eye Res. 124, 37-47 (2014).</li><li>Denton, M. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatially+correlated+microthermography+maps+threshold+temperature+in+laser-induced+damage.">Spatially correlated microthermography maps threshold temperature in laser-induced damage.</a> J Biomed Optics. 16 (3), (2011).</li><li>Morgan, C. M., Schatz, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atrophic+creep+of+the+retinal+pigment+epithelium+after+focal+macular+photocoagulation.">Atrophic creep of the retinal pigment epithelium after focal macular photocoagulation.</a> Ophthalmology. 96 (1), 96-103 (1989).</li></ol>

In discussing temperature-related biological cellular responses, not only the temperature, but also the time duration of the increased temperature, is of importance, since most biochemical processes are time-dependent. Particularly in the field of laser-induced hyperthermia in ophthalmology, due to the short time range-from milliseconds to seconds-it is difficult to investigate cellular thermal effects with precise temperature control. Therefore, a laser irradiation setup suitable for the cell culture model and with an o...

Understanding temperature-dependent cell biological responses is of great importance to successful hyperthermia treatments. Retinal laser photocoagulation with a thermal laser, used in ophthalmology, is one of the most established laser treatments in medicine. Visible light, mostly from green to yellow wavelengths, is used in retinal laser treatment. The light is highly absorbed by the melanin in retinal pigment epithelial (RPE) cells, which form the outermost cell monolayer of the retina. There has been recent interest among physicians and researchers in very mild thermal irradiation (sub-visible photocoagulation) as a new therapeutic strategy for different kinds of retinal disorders1,2. Following this trend, our interest is in sub-lethally heating RPE cells under precise temperature control, a technique called temperature-controlled photothermal therapy (TC-PTT).
Recent optoacoustic technology from our institute has allowed for the real-time measurement of temperature increases at irradiated sites in the retina. This enables control over the temperature increase during irradiation3. However, since sub-lethal hyperthermia on the retina, caused by heating RPE cells sub-lethally, has not been previously considered due to the impossibility of measuring and controlling the temperature, the temperature-dependent cell responses of RPE cells following thermal laser irradiation has been studied very little to date. Moreover, not only has the temperature difference not been discussed in detail, but also the difference in the cell behavior of the surviving cells after sub-lethal and lethal irradiation. Therefore, to gather scientific evidence on TC-PTT-based treatments, we aim to elucidate the temperature-dependent RPE cell biological responses and their mechanisms using in vitro experimental setups.
For this purpose, it is necessary to establish a cell-heating setup that meets the following conditions: 1) a possibility for fast temperature increases, 2) a precisely controlled time and temperature, and 3) a relatively high number of examined cells for biological experiments. Regarding the heating method, a clinical laser, such as a frequency-doubled Nd.YAG laser (532 nm), is unfortunately unsuitable for cell culture heating. This is because of the strongly reduced number of melanosomes in cultured RPE cells. The laser light absorption might be inhomogeneous, and the temperature increase at the cellular level is variable between experiments, even when irradiated with same radiation power. Several previous studies have reported the use of black paper beneath the dish bottom during irradiation4 or the use of additional melanosomes that are phagocytized by the culture cells before the experiments5,6. Many of the in vitro biological studies to assess hyperthermia-induced cell responses have been performed using a hot plate, a water bath, or a CO2 incubator with a temperature setting7. These methods require a long heating period because it takes some time (i.e., several minutes) to reach the desired temperature. Furthermore, using these methods, it is difficult to obtain a detailed thermal history (i.e., temperature multiplied by time) at the cellular level. Moreover, the temperature among the cells at different positions in one culture dish may differ due to variable temperature diffusion. In most cases, this temporal and spatial temperature information during hyperthermia has not been taken into consideration for biological analyses, even though biological cell response may be critically affected by the temperature and the time duration of the increased temperature.
To overcome these problems, a continuous-wave thulium laser was used here to heat the cells. Thulium laser radiation (&#955; = 1.94 &#181;m) is strongly absorbed by water8, and the cells at the bottom of the culture dish are thermally stimulated solely through thermal diffusion. The laser fiber with a 365-&#181;m diameter is set about 12 cm above the culture dish, without any optics in between. The laser beam diameter diverges such that it is almost equivalent to the inner diameter of the culture dish (30 mm) at the surface of the culture medium.With a consistent amount of culture medium, it is possible to irradiate the cells with the temperature increase of high repeatability. Variable power settings enable irradiation with up to 20 W, and the medium temperature at the cellular level may be increased up to &#916;T &#8776; 26 &#176;C in 10 s.
By modifying the irradiation conditions, it is also possible to change the laser beam profile to vary the temperature distribution in a culture dish. For example, it is possible to investigate with a Gaussian-like temperature distribution, as in the current study, or with a homogeneous temperature distribution. The latter may be advantageous for investigating the effects of temperature-dependent cell responses more specifically for sub-lethal temperature increases, but not for cell death stress or wound healing responses.
Altogether, thulium laser irradiation may enable the investigation of different kinds of biological factors, such as gene/protein expression, cell death kinetics, cell proliferation, and cell functionality development, after different thermal exposures.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco's Modified Eagle's Medium - high glucose</td>
			<td>Sigma-Aldrich</td>
			<td>D5796-500ML</td>
			<td>Add (2)-(4) before use. Warm in 37&#176;C water bath before use.</td>
		</tr>
		<tr>
			<td>Antibiotic Antimycotic Solution (100&#215;)</td>
			<td>Sigma-Aldrich</td>
			<td>A5955-100ML</td>
			<td>Containing 10000 units penicillin, 10 mg streptomycin and 25 &#956;g Amphotericin B in 1ml. Add 5.5 ml in 500 ml medium bottle (1) before use.</td>
		</tr>
		<tr>
			<td>Sodium pyruvate (100 mM)</td>
			<td>Sigma-Aldrich</td>
			<td>S8636-100ML</td>
			<td>Add 5.5 ml in 500 ml medium bottle (1) before use (final concentration: 1 mM)</td>
		</tr>
		<tr>
			<td>Porcine serum</td>
			<td>Sigma-Aldrich</td>
			<td>12736C-500ML</td>
			<td>Add 50 ml in 500 ml medium bottole (1) before use (final: 10%)</td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (PBS)</td>
			<td>Sigma-Aldrich</td>
			<td>D8537-500ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin from porcine pancreas</td>
			<td>Sigma-Aldrich</td>
			<td>T4799-25G</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylenediaminetetraacetic acid (EDTA)</td>
			<td>Sigma-Aldrich</td>
			<td>ED-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Human VEGF Quantikine ELISA Kit</td>
			<td>R&#38;D System</td>
			<td>DVE00</td>
			<td></td>
		</tr>
		<tr>
			<td>Oxiselect Total Glutathione Assay Kit</td>
			<td>Cell Biolabs, Inc</td>
			<td>STA-312</td>
			<td></td>
		</tr>
		<tr>
			<td>Apoptotic/Necrotic/Healthy Cells Detection Kit</td>
			<td>PromoKine</td>
			<td>PK-CA707-30018</td>
			<td></td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Equipments</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Thulium laser</td>
			<td>Starmedtec GmbH</td>
			<td>Prototype</td>
			<td>0-20 W</td>
		</tr>
		<tr>
			<td>365 mm core diameter fiber</td>
			<td>LASER COMPONENTS Germany</td>
			<td>CF01493-52</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermocouple</td>
			<td>Omega Engineering Inc</td>
			<td>HYP-0- 33-1-T-G-60-SMPW-M</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating plate</td>
			<td>MEDAX</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microplate reader (spectrofluorometer)</td>
			<td>Molecular Device</td>
			<td>Spectramax M4</td>
			<td></td>
		</tr>
		<tr>
			<td>cell homogenizer</td>
			<td>QIAGEN</td>
			<td>TissueLyser LT</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescence microscope</td>
			<td>Nikon</td>
			<td>ECLIPSE Ti</td>
			<td></td>
		</tr>
		<tr>
			<td>mathematical software program</td>
			<td>The Mathworks. Inc</td>
			<td>MATLAB Release 2015b</td>
			<td></td>
		</tr>
		<tr>
			<td>system-design platform</td>
			<td>National Instrument</td>
			<td>Labview</td>
			<td>Laboratory Virtual Instrument Engineering Workbench</td>
		</tr>
	</tbody>
</table>

continuous-wave thulium laser for heating cultured cells to investigate cellular thermal effects

An original method to heat cultured cells using a 1.94 &#181;m continuous-wave thulium laser for biological assessment is introduced here. Thulium laser radiation is strongly absorbed by water, and the cells at the bottom of the culture dish are heated through thermal diffusion. A laser fiber with a diameter of 365 &#181;m is set about 12 cm above the culture dish, without any optics, such that the laser beam diameter is almost equivalent to the inner diameter of the culture dish (30 mm). By keeping a consistent amount of culture medium in each experiment, it is possible to irradiate the cells with a highly reproducible temperature increase.
To calibrate the temperature increase and its distribution in one cell culture dish for each power setting, the temperature was measured during 10 s of irradiation at different positions and at the cellular level. The temperature distribution was represented using a mathematical graphics software program, and its pattern across the culture dish was in Gaussian form. After laser irradiation, different biological experiments could be performed to assess temperature-dependent cell responses. In this manuscript, viability staining (i.e., distinguishing live, apoptotic, and dead cells) is introduced to help determine the threshold temperatures for cell apoptosis and death after different points in time.
The advantages of this method are the preciseness of the temperature and the time of heating, as well as its high efficiency in heating cells in a whole cell culture dish. Furthermore, it allows for study with a wide variety of temperatures and time durations, which can be well-controlled by a computerized operating system.

Temperature distribution after different power settings
All temperature developments for each single irradiation were monitored in the temperature calibration. From this data, the maximal temperature at the measured point was obtained and defined as Tmax (&#176;C). As shown in Figure 3A, the program was executed at the time point when the culture dish was placed on the heating plate. After t...

Watch this Scientific Journal Video about Continuous-wave Thulium Laser for Heating Cultured Cells to Investigate Cellular Thermal Effects at JoVE.com

Continuous-wave Thulium Laser for Heating Cultured Cells to Investigate Cellular Thermal Effects

An original experimental setup for heating cells in a culture dish using 1.94 &#181;m continuous-wave laser radiation is introduced here. Using this method, the biological responses of retinal pigment epithelial (RPE) cells after different thermal exposures can be investigated.

An original method to heat cultured cells using a 1.94 &#181;m continuous-wave thulium laser for biological assessment is introduced here. Thulium laser ...

The overall goal of this procedure is to study thermal dose-dependent cell biological responses in vitro by heating cultured cells with precise temperature and time control. This method can help answer key questions in fields investigating cell or tissue responses to hyperthermia such as the study of retinal laser treatment. The main advantage of this technique is a quick heating of cells and a precise control over heating duration allowing a high reproducible thermal exposure during experiments.Though this method can provide insight into the responses of cultured retinal pigment epithelial cells to thermal laser irradiation, it can also be applied to other models such as cancer cells. We first had the idea for this method when heating melanin containing cells with visible laser light. However, this resulted in varying temperature profiles owing to variations in pigmentation.To begin to procedure, place a hot plate in an adjustable metal lab stand on a clean bench. Set the hot plate to 39 degrees Celsius. Secure a 0.22 NA fiber with a core diameter of 365 micrometers to the horizontal arm of the stand.Position the metal arm over the hot plate and adjust the stand so that the fiber tip is 12 centimeters above the hot plate. Connect a 1.94 micrometer 20 watt Thulium laser with a 365 nanometer one milliwatt aiming beam to the fiber tip. Place a culture dish 30 millimeters in diameter on the hot plate.Carefully trace the circumference of the dish on the hot plate surface and then remove the dish. Turn on the aiming beam and adjust the stand until the center of the beam spot on the hot plate matches the traced circle. Then turn off the aiming beam.To begin the temperature calibration procedure, heat the tip of a 20 gauge needle with a Bunsen burner. With the heated needle tip, pierce the 30 millimeter diameter culture dish close to the bottom at four points 90 degrees apart to make holes about 300 micrometers in diameter. Place electrical tape over the holes.Use a fine needle to punch an approximately 200 micrometer diameter hole through the tape covering each hole. On the underside of the culture dish, draw a line between each pair of holes 180 degrees apart. Starting at the intersection of the lines, mark every three millimeters radially along each line to designate the 21 measurement points.Then place exactly 1.2 milliliters of fresh culture medium pre-warmed to 37 degrees Celsius in the dish. Cover the dish and set the dish in the traced circle on the hot plate. Connect a thermocouple with a diameter of 200 micrometers to the laser control computer and open the temperature calibration protocol.Insert the thermocouple into one of the holes in the dish so that the tip is on the bottom of the dish at one of the mark's locations. It is very important to check if the tip of the thermocouple is touching the bottom of the dish at the measured precision because temperature may vary according to depth. Wait for the culture medium to stabilize at 37 degrees Celsius.Then turn on the Thulium laser and set the laser power to the desired starting level. Verify that the preheating durations are set to 140 and eight seconds and then start the preheating irradiation sequence. After 140 seconds as cued by an audible beep, immediately remove the cover of the culture dish.Wait while the preheating finishes and the 10-second irradiation occurs. Then immediately cover the dish. Measure the temperature at the 21 marks locations in this way.Perform this procedure three times each at three watt power intervals spanning the laser power range. Once finished, turn off the thulium laser. Export and analyze the temperature data.Prior to the experiment, culture rental pigment epithelial cells in 30 diameter culture dishes. Maintain the cell cultures at 37 degrees Celsius in a 5%carbon dioxide atmosphere and check them using a live cell imaging system. One hour before irradiation, replace the culture medium in each dish with exactly 1.2 milliliters of fresh culture medium.Return the cultures to the incubator. Verify that the irradiation station is ready and that the hot plate is set to 39 degrees Celsius. When ready to begin irradiation, start the thulium laser at the desired power.Open the experiment protocol and verify that the preheating durations are set to 140 and eight seconds. Place an RPE cell culture in a closed dish on the marked position on the hot plate and immediately start the 140 and eight second preheating irradiation sequence. Remove the dish cover after 140 seconds of preheating.Wait while the preheating finishes and the 10-second irradiation occurs. Immediately cover the dish, wait seven seconds, and then return the dish to the incubator. Irradiate additional samples at increasing laser power levels.When finished, turn off the thulium laser. To begin the cell viability assessment, wash the irradiated cells with PBS. Obtain a kit capable of differentiating live apoptotic and necrotic cells.Then in low light, combine 500 microliters of binding buffer with 25 microliters of ethidium homodimer-3, FITC annexin and Hoechst 33342. Incubate the cells in this staining solution at room temperature for 15 minutes. Then wash the cells with 1X binding buffer twice.Replace the binding buffer with PBS and place the cell on the stage of a fluorescence microscope that has DAPI, FITC and TRITC filters. Set the microscope light path to the ocular lens and select the DAPI filter. Turn on the illumination light and find the focus plane with a 4X objective lens.Set the light path to the microscope camera. Use the microscope imaging software to center and focus the image. Define the parameters for image acquisition using the DAPI filter.Repeat the focusing process and image acquisition setup with the FITC and TRITC filters. Then use the imaging software to acquire multiple images with three filter sets across the dish and combine them into a single image of the whole culture dish. Use analytical software to determine the temperature thresholds for apoptosis and cell death.The proportional relationship between the maximal temperature increase at the center of a cell culture dish and the laser power was determined by the described thermal calibration procedure. The maximal temperature distribution across the cell culture dish was then fit to a Gaussian function. Three staining patterns were observed following irradiation.No viability change was observed in cultures subjected to temperatures at or below 43 degrees Celsius. Apoptosis was first observed three hours after irradiation at 47 degrees Celsius. Cell death was observed later than three hours after 51 degrees Celsius and higher.The mean threshold temperatures for apoptosis and cell death were then determined by applying the average of measured radii of the dead and apoptotic areas to the Gaussian function describing the temperature distribution. Following this procedure, irradiations can be performed under many different conditions such as different laser profiles, spot sizes and irradiation times. This can help to understand and investigate questions related to individual timed temperature causes on the cellular level.After watching this video, you should have good understanding of how to heat the cell culture with good control over temperature and time. This may ride on the possibilities for studying biological responses to different thermal irradiation conditions. Don't forget that working with lasers can be very hazardous for your eyes and skin.Stay informed about laser irradiation safety training. Always wear appropriate safety glasses, lab coat and gloves when performing this procedure.

Research

JoVE Journal

Biology

Studying the Effects of Matrix Stiffness on Cellular Function using Acrylamide-based Hydrogels

Tissue stiffness is an important determinant of cellular function, and changes in tissue stiffness are commonly associated with fibrosis, cancer and ...

Adenovirus-mediated Genetic Removal of Signaling Molecules in Cultured Primary Mouse Embryonic Fibroblasts

The ability to genetically remove specific components of various cell signalling cascades has been an integral tool in modern signal transduction ...

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

Oxygen is essential for all metazoans to survive, with one known exception1. Decreased O2 availability (hypoxia) can arise during states of disease, ...

Chromosome Preparation From Cultured Cells

Chromosome (cytogenetic) analysis is widely used for the detection of chromosome instability. When followed by G-banding and molecular techniques such as ...

Organelle Transport in Cultured Drosophila Cells: S2 Cell Line and Primary Neurons.

Organelle Transport in Cultured Drosophila Cells: S2 Cell Line and Primary Neurons.

Drosophila S2 cells plated on a coverslip in the presence of any actin-depolymerizing drug form long unbranched processes filled with uniformly polarized ...

siRNA Screening to Identify Ubiquitin and Ubiquitin-like System Regulators of Biological Pathways in Cultured Mammalian Cells

Post-translational modification of proteins with ubiquitin and ubiquitin-like molecules (UBLs) is emerging as a dynamic cellular signaling network that ...

Quantitation of Endothelial Cell Adhesiveness In Vitro

Quantitation of Endothelial Cell Adhesiveness In Vitro

One of the cardinal processes of inflammation is the infiltration of immune cells from the lumen of the blood vessel to the surrounding tissue. This ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

Using Microfluidic Devices to Measure Lifespan and Cellular Phenotypes in Single Budding Yeast Cells

Budding yeast Saccharomyces cerevisiae is an important model organism in aging research. Genetic studies have revealed many genes with conserved effects ...

A Graphical User Interface for Software-assisted Tracking of Protein Concentration in Dynamic Cellular Protrusions

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex ...