Tag: zeta potential

Recap of my research journey (2004 to present)

April 19, 2024

My research journey started in May 2004 with a UROP (Undergraduate Research Opportunities Programme) project on biosorption of copper using local marine seaweed in Prof. Chen Jiaping’s lab at National University of Singapore. Currently, I am working on developing quantitative polymerase chain reaction (qPCR) assay and device for detecting Helicobacter pylori in stomach gastric samples. … More Recap of my research journey (2004 to present)

Explaining the manuscript: “Bacterial surface charge in layers”

June 18, 2022

During my master’s study, I undertook a project examining the effect of different wash buffers on bacterial surface charge measurement. Specifically, the hypothesis was that different wash buffers have different composition and ionic strength, and would thus exert different effects on removal of nonspecifically adsorbed ions and biomolecules on the cell surface. This would in … More Explaining the manuscript: “Bacterial surface charge in layers”

Challenges faced in the work, Zeta potential of bacterial cells: Effect of wash buffers

May 28, 2022

During my master’s study, I did some work on understanding the effect of wash buffers on bacterial surface charge of bacterial cells in a work entitled: “Zeta potential of bacterial cells: Effect of wash buffer”. Basically, the hypothesis that I tested was the extent in which different wash buffer would remove the ions and biomolecules … More Challenges faced in the work, Zeta potential of bacterial cells: Effect of wash buffers

Surface charge characteristics of Bacillus subtilis NRS-762

March 17, 2020

Bacillus subtilis is a common soil bacterium with application potential in the expression of recombinant proteins in biotechnology. A recent study sought to understand the surface charge characteristics of B. subtilis NRS-762 (ATCC 8473) through the use of zeta potential measurement. Given that zeta potential is a proxy parameter for surface charge, its measurement could … More Surface charge characteristics of Bacillus subtilis NRS-762

Nonspecific adsorption of ions and biomolecules mask the real surface charge of bacterial cells

February 15, 2020

Various proteins and biomolecules decorate the surface of bacterial cells. Whether tethered to the outer membrane of Gram-negative bacteria or adhering to the peptidoglycan layer of Gram-positive bacteria, these biomolecules endow the cell surface with an electrical charge and are responsible for various signalling and recognition processes mediated by cell surface receptors. However, in addition … More Nonspecific adsorption of ions and biomolecules mask the real surface charge of bacterial cells

Zeta potential of Escherichia coli DH5α cells grown in different growth media

January 15, 2020

Bacterial cells adapt to growth in different growth medium. Thus, could the cell surface structures and, by extension, surface charge characteristics of bacterial cells change as a result of growth in different growth medium. In addition, different growth medium comprises different sets of ions and metabolites for aiding growth of cells, could these ions and … More Zeta potential of Escherichia coli DH5α cells grown in different growth media

Zeta potential measurement can be influenced by particle concentration

January 10, 2020

Zeta potential is commonly used as a proxy for cell surface charge, but is zeta potential dependent on particle concentration? The answer is yes in the case of high particle concentration.   From a theoretical standpoint, zeta potential measurement comes from the direct measurement of light scattered off moving particles in a fluid. In the … More Zeta potential measurement can be influenced by particle concentration

Electroosmotic flow in zeta potential analysis

January 3, 2020

Microelectrophoresis light scattering is commonly used to measure the zeta potential of cells, which is a proxy parameter for the cell surface charge. Briefly, the technique entails the measurement of movement of cells within a fluid upon application of an electric field. Thus, depending on the amount of surface charge present on cells, different rates … More Electroosmotic flow in zeta potential analysis

Wash buffer of ionic strength 0.15M could unmask the real surface charge of Bacillus subtilis NRS-762 cells

July 26, 2018

Bacterial cells in solution would inevitably carry a layer of nonspecifically adsorbed ions and molecules on their cell surface resulting from contact with the solution. This layer of nonspecifically adsorbed ions and molecules would thus masks the real surface charge of the bacteria. To reveal the real surface charge of bacteria during microelectrophoretic measurement of … More Wash buffer of ionic strength 0.15M could unmask the real surface charge of Bacillus subtilis NRS-762 cells

Effect of wash buffers on zeta potential measurement of bacterial cells

March 19, 2018

Nonspecific adsorption of ions and metabolites from the growth medium on the bacterial cell surface is inevitable given the presence of various functional groups on the cell envelope. Thus, various wash buffers such as phosphate buffered saline and 0.1M sodium nitrate have been used in repeated steps of centrifugation and washing for removing the nonspecifically … More Effect of wash buffers on zeta potential measurement of bacterial cells