Table 4.12 and Table 4.13 shows the readings for the tests conducted at pH7 for the cationic dye and anionic dye solution. From the Figure 4.9 and Figure 4.10, it can be seen that the maximum color removal obtained is 85.67%, 83.30% and 78.93% for cationic dye and 71.83%, 64.08% and 62.91% for initial dye concentration of 25, 50 and 75mg/L respectively at WTR dose of 120mg/L. The trends of decreasing color removal continued with the increase in pH as the least readings were obtained at pH7.
This lab could have contained errors. The errors could have happened when performing the lab. Some of the possible errors in this lab are:
The goal of this experiment is to prepare a photosensitive solution and explore its properties. While analyzing the solution, one will learn how to successfully handle these sensitive chemicals and then establish its properties via spectrophotometry.
 McCray, J. A., & Trentham, D. R. (1989). Properties and uses of photoreactive caged compounds. Annual review of biophysics and biophysical chemistry,18(1), 239-270.
Photodynamic Medicine : From Bench to Clinic. Royal Society of Chemistry, 2016. Comprehensive Series in Photochemical & Photobiological Sciences. EBSCOhost, proxygsu-satl.galileo.usg.edu/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=nlebk&AN=1367409&site=eds-live&scope=site.
The concentrations of L-arginine and L-asparagine were measured in the range 0.110 mM. Data was collected from the fluorescence intensity of the Arg-and Asn-sensing membranes at the two emission wavelengths (λem = 565 and 625 nm) at an excitation wavelength of 460 nm (λex = 460 nm). The fluorescence spectra for detecting L-Arg and L-Asn were measured using a multifunctional fluorescence microtiter plate reader (Saphire2, Tecan GmbH, Wien, Austria).
The aim of this investigation was to determine the effect of ethanol on the membrane permeability using Beta vulgaris. Beta vulgaris contains red pigments called betalain sequestered in vacuoles. The cell membrane is generally impermeable to betalain as this pigment is relatively large and cannot pass through the membrane by diffusion. (123HelpMe.com, 2015) However, by increasing the permeability of the cell membrane, betalain can leach out of the cell and colour the liquid red. The colour intensity of the solution due to leakage of betalain is proportional to the membrane permeability. To quantify the colour intensity, the light absorbance of the solutions containing a Beta vulgaris cube were measured by a spectrophotometer. These measurements were used to analyse the membrane permeability. (Flinders University, 2015)
TThe authors did a series of experiments and demonstrated that the matrine compound, extracted from the root of Sophorae flavescens exerts antidepressant effect in animal models and in parallel verified that the compound activates the mTOR pathway. In addition, they found that the antidepressant effect of matrine, as well as the expression of neurogenesis markers promoted by the compound, were blocked by inhibitors of mTOR signaling.
Rhodamine B appears green in powder form but when added to water turns a vivid fluorescent pink.
In order to study the radioactivity of thorium, Soddy and Rutherford preformed an experiment in which ammonia was added to a solution of thorium and thorium hydroxide was precipitated out. This observation eventually led to the discovery of the radioactive properties found within the remaining solution. Both scientists then concluded that this was an outcome of a highly radioactive compound known as thorium-X. Using these experimental observations, a series of detailed testing was preformed regarding the radioactive behavior of the precipitate and remaining solution. Over the course of a few weeks, it became evident that radioactive decay is an effect of a variety of chemical reactions occurring inside the atom. Additional evidence that supported
Fluorescent properties are used to study protein and small molecule interactions. Fluorescent spectrophotometry determined the excitation wavelength of eosin isothiocyanate to be 525 nm and its emission wavelength was 545 nm. Glycogen phosphorylase was similarly studied. The excitation wavelength was 330 nm and the emission wavelength was 360 nm. The emission wavelength could be indicative of the presence of the fluorophore, tryptophan. The potential interaction between bovine serum albumin (BSA) and 1-anilino-8-naphthalene sulfonic acid (ANS) was studied through fluorescence and fluorescence resonance energy transfer (FRET). BSA had an emission wavelength of 358 nm which could also be indicative of a tryptophan. When BSA and ANS were mixed together, the emission wavelength was longer suggesting that the molecules interact with each other and follow FRET.
Confocal microscopy uses a laser that produces excitation light. This laser light reflects off of a dichroic mirror and then the laser light hits two mirrors that are mounted on motors. The mirrors then scan the laser light across the sample. Dye that is found in the sample then fluoresces (Weeks, 2003). Filamin was labeled with a red fluorescent label rhodamine (TRITC) and actin was labeled with the green fluorescent label fluoroscein (FITC) which was conjugated to the actin-binding fungal toxin phalloidin. The emitted light from the dyes passes back through the mirrors and passes through the dichroic mirror and is focuses into a pinhole. With confocal microscopy, a complete image of the sample is
It is of strong interest to molecular biologists because of the strong light emission of 508 nm under UV light. UV wavelengths excite the fluorophore, contained in the Ser - Tyr - Gly sequence near GFP's N-terminus, and a bright green fluorescence is given off as a result (Niwa et al., 1996). GFP can be successfully tagged to many proteins without disturbing their function (Feilmeier et al., 2000). This allows scientists to exploit the protein for its usefulness in marking proteins in vivo. GFP tagging has many applications. It can be used to study gene expression by inserting gfp after a promotor in the plasmid, so that if expressed, the colony expressing the gene of interest can be identified by a green fluorescence of GFP under UV light (Feilmeier et al., 2000). Specific cellular organelles can be tagged, such as the endoplasmic reticulum, to visualize protein localization and networking inside the living cell. GFP can also be used to monitor cofactor levels within a cell in real time. For example, when GFP was tagged to proteins that contain a receptor sensitive to Ca2+, they interacted in a way so that the fluorescence of the fusion protein was proportional to the calcium ion concentration with less than a 1 second lag in the cell (Romoser et al., 1997). Throughout the decades, GFP mutants have been created to give brighter emission and different wavelengths. Researchers can track separate cell pathways at the same time, since different proteins can
Fluorescence microscopy uses ultraviolet light as its light source that allows the resolution of the object to increase. Fluorescence microscopy contains a barrier filter that reduces any undesired stray of light other than the emission wavelength that might reach the observers eye. Light emitted by the specimen’s fluorophore for viewing is focused and magnified by the objective lens.
For cellular biology analyses, I have two years of training in confocal microscopy to perform complex experiments including: Fluorescence Resonance Energy Transfer, Fluorescence Recovery After Photobleaching, real time live cell imaging. These provided the means to analyze both the spatial and temporal properties of interacting proteins using microscopy. Cell