TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
Cytotoxic assay Cytotoxicity is described as the quality of being toxic to cells. The technique is used to measuring dead cell protease activity, in which they have lost membrane integrity. There are several ways used to measuring cytotoxicity, but generally involved in the assessment of cell membrane integrity. Vital dyes such as propidium iodide or trypan blue can be used to estimate the membrane integrity by measuring the ATP content or protease biomarker with the MTT redox potential assay. Many of these assays are involved in colorimetric or fluorescence detection.
Substrate concentration basically means the amount used for the substrate. The substrate in our experiment was 0.1% hydrogen peroxide. The 0.1% is the concentration amount. Just like temperature and pH, substrate concentration can speed the reaction only up to a certain limit. When we mixed pH 3 enzyme tube with substrate tube, we used 0.3 mL of hydrogen peroxide, but if we were to increase the amount, then the experiment would have been faster.
Therefore, they can undergo electrophilic substitution reaction and the attacking species, in this case, will be an electrophile. The +M effect will result in the concentration of electron density at ortho −and para −positions. However, electrophilic substitution reactions with respect to the haloarene reactions are slow in comparison to benzene reactions. This is because the halogen group present in haloarenes are deactivating because of the –I effect. Hence, electrons are withdrawn from the benzene ring.
meningitidis has extensive mechanisms to elude the host immune system, of which tactics to evade complement deposition are of major importance. The main mechanism is the recruitment of a human negative regulator of the complement system, fH, by the membrane protein fHbp. This binding, by preventing the assembly of C3 convertase, inhibits the deposition of complement on the bacterial surface and increases its chances of survival. In addition, N. meningitidis can exploit host weakness by upregulating the expression of proteins involved in immune evasion in response to elevated temperature, as is the case in fever. Future research should seek to target specific antigens on the surface and inhibitors of the fHbp-fH interaction to be able to treat or prevent this disease that can have severe
A quantitative structure-activity relationship (QSAR) is an equation which correlates measurable or calculable physical or molecular properties to some specific biological activity. Once this relationship has been determined, it is possible to predict the biological activity of related drug candidates before they are put through expensive and time-consuming biological testing. The electronic effects of a substituent have an effect on the ionisation or polarity of a drug. This in turn may affect how easily a drug can pass through
SAMPLE REQUIREMENT: Type of specimen: Serum (Blood collected in Plain tube and centrifuged to separate serum). PRINCIPLE OF TEST: In the presence of a strong base such as NaOH, picrate reacts with creatinine to form a red chromophore. The rate of increasing absorbance at 510nm due to the formation of this chromophore is directly proportional to the creatinine concentration in the sample and is measured using a Bichromatic (510,600nm) rate technique. To correct for non-specific reaction caused by serum/plasma pseudo-creatinine chromogens, including proteins and ketones, the results for serum or plasma are corrected by -18 μmol/L (-0.2 mg/dL). (2, 4, 14-18) Alkaline pH (NaOH) Creatinine + picrate red chromophore (absorbs at 510nm) EQUIPMENTS & APPARATUS: Siemens Dimension® clinical chemistry analyzer (X pand and RxL Max) Flex reagent cartridge, Assay Cups, tips, pipettes.
Increased sensitivity is achieved by biuret complexes that react with phosphomolybdotungstate acid reagent (Folin & Ciocalteu’s Phenol reagent) to produce an altered color that is absorbed at 750 nm. Greater molar extinction coefficients are achieved in the resulting compound, which lends to the increased sensitivity to lesser amounts of protein. This method characteristically has an even more increased vulnerability than the Biuret method to ammonium salts, reducing agents, and detergents which can alter the results for similar reasons. For this reason, the Lowry experiment should be conducted first to reduce the likeliness that the glassware would be contaminated with high concentrations of protein
When the results for the first test tube were recorded, then the next solution/mixture was prepared. The second test tube was exactly the same as the first, the only difference being that the SPM was this time set to 35oC. The temperature of the SPM gets increased by 1oC for every test tube solution, until test tube 7 with an SPM temperature of 40oC. After all the absorbencies for the varying temperatures had been recorded – the product concentration of each test tube solution was calculated using the absorbency readings at 10 minutes for each respective test tube mixture. The product concentration was calculated using Beer-Lamberts’ law of A = ECL.
To indicate the separation effect for different ratio of p-xylene to methyl acetate more clearly, Fig. 4 shows the dependence of selectivity on the water/acetic acid mass ratio in the initial mixture for various different ratios of p-xylene to methyl acetate in the initial mixture. These results reveal the general capability of mixed solvent to extract acetic acid from the aqueous phase at different feed composition. As mentioned earlier, methyl acetate has been put up in this industrial operation, since it was available as the byproduct of terephthalic acid production. As can be seen in Fig.4, a higher ratio of p-xylene to methyl acetate can produce higher selectivity of acetic acid against water.
Daphnia are grown as fish food, and used to test ecotoxicity. Ecotoxicology is defined as, "the branch of toxicology concerned with the study of toxic effects, caused by natural or synthetic pollutants, to the constituents of ecosystems, animal (including human), vegetable and microbial, in an integral context” (Truhaut, 1977). The experiment discussed in this lab report was performed on daphnia, exploiting their transparency which renders them the ideal organism, to test effects of various stimulus on cardiac activity. Past research studies have found ethanol to produce a depressant effect, one similar to the depressant effects of melatonin, and GABA. In contrast, Corotto (2010) has experimented on stimulants, e.g.
Mannitol high salt testing is done in order to determine if the bacteria is salt tolerant and can ferment mannitol. Catalase activity test establishes whether the bacterium produces the enzyme catalase. The eosin methylene blue test or EMB, inhibits the growth of gram positive bacteria and tests whether or not gram negative bacteria can ferment lactose. Lactose fermentation testing is done to see if the bacterium is capable of fermenting sugar by testing for acid and gas production. These are the possible tests that are needed in order to identify unknown
Collecting small fractions is essential in column chromatography because they can be combined together; large fractions can lead to multiple compounds in a specific fraction. The purpose of this experiment was to isolate the three components of Excedrin using column chromatography. Thin layer chromatography (TLC) was used to determine when each of the components had been fully eluted from the column. If there was an overlap in fractions between two components, liquid- liquid extraction was done to separate them. The compounds were characterized via NMR instrumentation and the percent recovery for each compound was calculated to determine whether the isolation was
Introduction: In the field of microbiology being able to identify a specific bacterial species is an important skill. In order to discover and being able to identify any microbial bacteria, there a list of test one must perform in order to come with the right microorganism. It is fundamental to be aware of the risk of toxify, the resistance to antibiotics and determining how to prevent its growth and being able to destroy this bacteria. By being able to run both physical and chemical test to determine the identity of the mystery microbe is a unique and useful skill in the field of medicine and microbiology. Each