2.6. Rejection and Passage
119 To easily go on study, β2-Microglobulin (β2-MG) and human serum albumin were replaced by
120 lysozyme (LZM) and Albumin from bovine serum (BSA). LZM and β2-MG have the similar molecular
121 weight as LZM is 14 KDa while β2-MG is 11.8 KDa. The molecules of them are both positive charge
122 and globulin. At the same time, isoelectric point of them is relatively similar (LZM was 4.6 and β2-
123 MG 5.7). The molecular weight of BSA is 67 KDa while human serum albumin is 69 KDa. BSA
124 rejection, Urea and LZM passage were measured in the same method as UF flux. After preflush the
125 membranes with the solute for about 30 minutes under temperature (25 °C), The BSA rejection, Urea
126 and LZM passage of membranes were
…show more content…
131 The urea and LZM passage was calculated by the following Equation (5): p r
C
P
C
(5)
132 where Cp and Cr (mg·L−1) are the concentrations of permeate and remaining solution. The
133 concentration of different solute is determined by UV-Vis spectrophotometer.
134 2.7. Hydrophilic Test
135 The hydrophilicity of membrane surface was characterized on the basis of water contact angle
136 measurement by YH-168A type contact angle goniometer. The membranes (2 × 2 cm) rinsed with
137 ethanol and then put in 60 °C ovens drying for 2 h. The contact angle was measured 10 s after water
138 dropted on the airside surface of membranes. At least eight measurements were averaged to get a
139 reliable value.
140 2.8. Protein adsorption
141 The protein adsorption experiments were carried out with BSA, which were dissolved in the
142 phosphate-buffered saline solution (PBS, pH 7.4) with a concentration of 1 mg·mL−1. The membranes
143 with an area of 10 cm × 10 cm were incubated in PBS solution for 24 h and then immersed in the
144 protein solution for 12 h at 25 °C. The BSA concentrations before and after membrane adsorption
145 were measured by UV-Vis
…show more content…
164
Membranes 2016, 6, x 5 of 15
2.8.3. Platelets Adhesion 165
A sample of 20 mL fresh heart blood was collected from healthy rabbit using centrifugal tubes. 166 The blood was mixed with sodium citrate as an anticoagulant (anticoagulant to blood ratio, 1:9 v/v), 167 and centrifuged at 200 g for 15 min at 4 °C to obtain platelet-rich plasma (PRP). Platelet-attached 168 membranes were coated with a gold layer and the FESEM images were recorded by Quanta 200 type 169 field emission scanning electron microscopy. 170
3. Results 171
3.1. Effect of PVP Molecular Weight on PVDF Membranes Structure and Performance 172
The PVDF membranes were prepared by non-solvent-induced phase separation (NIPS). A series 173 of modified PVDF membranes were prepared by blended with PEG and PVP. The PVDF content was 174 22 wt. %. PEG content was 15.8 wt. % and PVP content was 3 wt. %. The cross-sectional SEM 175 micrograph of virgin PVDF membrane (PEG 18.8 wt. %) is M-0. The cross-sectional SEM micrographs 176 of the modified PVDF membranes are M-a, M-b and M-c with PVP molecular weights 6 KDa, 10 KDa 177 and 30 KDa, respectively.
A. The "Insulin".. World Book. 2005 Edition. 2005. The 'Secondary' of 308. The.
... retinol release may function near the membrane surface at near-neutral bulk pH (Ptitsyn et.al. 1993).
Abstract/Summary: “Proteins account for more than 50% of the dry weight of most cells, and they are instrumental in almost everything organisms do” (Campbell, 1999). The significance of proteins to the continuation of our biological systems is undeniable, and a study of how to quantify proteins seems an appropriate introduction to our studies of biology. In order to study proteins we must first know how to separate then quantify the amount using basic principles of experimental design such as a standard curve. In this experiment we wish to quantify the amount of previously extracted protein by measuring the absorbance of the unknown amount and determining its concentration by overlaying it against a standard curve of the absorbance of known concentrations of the protein. We used the dye agent Bradford Protein Assay to get an absorbance of 0.078, 0.143, 0.393, 0.473, and 0.527 at the protein’s respective concentrations of 0.28, 0.56, 0.84, 1.12, and 1.40 mg/mL. When a best-fit line was applied to the standard curve, and the absorbance of our unknown concentration (0.317 A) plotted, we estimated a concentration of around 0.84 mg/mL of protein. Our calculations indicated a quantity of 168 mg of protein, which was an approximately 8.96% yield of the projected 1875 mg that was expected. Errors that may have led to this small yield percentage may have stemmed from our previous lab and our initial attempts to extract the desired amount of protein.
After five the test tube was removed and cooled to room temperature. Three more test tubes were obtained and labeled 1, 2, and 3. The correct reagent was added to each test tube as seen. The spectrophotometer was adjusted
In figure 1.2, a major correlation between absorbance and percent hemolysis cannot be seen because the values fluctuated tremendously. On the contrary, it follows a pattern whereby a large value of absorbance gives a large value of percent hemolysis. In tubes 1 through 6 and the control hemolysis occurred, but in tubes 7 through 11 the red blood cells remained the same. The calculated osmolarity increased from 31.034 mOsm/kg to 341.352 mOsm/kg, thus displaying a negative slope between osmolarity and percent hemolysis. In other words, the NaCl concentration on the outside of the erythrocytes was larger than the inside, thus causing osmolarity to increase. Therefore, the green light from the colorimeter did not absorbed as much erythrocytes because water was unable to permeate the cells. In solutions 10 and 11, absorbance nor hemolysis did not take place because of the 0 values which means that the red light completely transmitted through these red blood
This curve is due to the fact that during the process the pores are not all clogged uniformly. Some are clogged while others are still open for the flux. The left pores which are still open exhibit high flux which leads to their clogging and fouling faster than the initial ones this symbolizes the sharp increase in the curve over time, leading to the complete closing of the membrane.
There are several reasons for the decrease of albumin functionality in the body. This usually happens when it is accompanied by a disease. Decreased albumin levels results from the body’s lowered production of protein and therefore a decreased amount of albumin [2]. Most commonly, low albumin can derived from low intake of protein. Malnutrition of protein can result in loss album...
In terms of polarity we discovered that magnesium oxide ,calcium carbonate and “ unknown 2” are polar enough to dissolve in water and not dissolve in hexane. Salicylic acid ,benzoic acid and “unknown 1” have similar polarities as both did not dissolve in water and hexane. As for pH, the salicylic and benzoic acid crystals were extremely acidic. Magnesium oxide was slightly acidic while calcium carbonate was slightly basic. In terms of the unknowns, both were neutral.
Small protein molecules move more quickly through the gel than larger proteins, resulting in a series of ‘bands’. Each band contains a protein of a particular size. These can be compared with standards of known sizes.
The experiment in this laboratory is to study pH and buffers. The pH is defined as the –log[H+] and measures the molar concentration of hydrogen ions. In the study of life, life can only be stabilized through a buffer. A buffer is a solution that is able to resist pH change and maintain the stability of everyday life. A buffer requires a weak acid and its conjugated base. When a solution such as an acid or base presents itself into the buffer solution, the buffer will neutralize the amount of acids or base added to the solution. As a result, pH maintains stabilization and cells are able to function properly. In this study experiment, sodium chloride is the tested solution. Sodium chloride (NaCl) is commonly known to many as salt. NaCl is tested
...ond sets of data concluded that sucrose, glucose, and salt are hypotonic solutions that will remove water from a cell due to their tonicity. In the final part of the lab, results concluded that water potential moves along its concentration gradient (high to low) in an attempt to maintain equilibrium. It was determined that the orange and green solutions were hypotonic as they added water to the cells, whereas the blue, red, purple and yellow solutions were hypertonic as they sucked water from the cells.
The details with respect to each of these items are discussed in the following sections. All experiments were based on the ability of the method to collect and analyze a 15-L air sample for each concentration tested. The sample preparation and analytical technique used during the method evaluation follow that described in reference 9.4. A revised method (9.1.) is also available.
Four drops of the unknown liquid (L21) or 50mg of solid unknown (S21) is mixed with 2mL of water in a test tube. 2mL of 3M sodium Hydroxide was then added. 3mL of iodine solution was added. The results of the reaction were
Saline solution is used to reverse hypotonic hydration. Are body cell membranes permeable to saline? Explain your response.