Influence of various colloidal surfactants on the stability of MS2 bacteriophage suspension. The charge distribution on the PCV2 virus surface

The Spectrophotometric Determination of the Patchy Surface Potential of Viruses Using pH-Sensitive Molecular Probes

“…The pK a value of the indicator was determined by the standard spectrophotometric method with potentiometric control of the pH of the medium. 19,21,28,38 The protocol involves a three-step procedure (see Figure 1 and eq 1): (i) working solutions preparation (the common series should include more than ten systems with varying pH of the medium); (ii) determination of the ratio H R In the first step, each student prepared 1−3 working solutions. The working solutions contained the indicator (1.0 × 10 −5 mol/ L), the MS2 bacteriophage (about 5 × 10 11 PFU/mL), and various additives of buffer components (acetic or phosphoric acid, alkali, etc.)…”

“…19 In the PCV2 bacteriophage solution, this difference was −0.19 for γ-dinitrophenol and +0.59 for hexamethoxy red. 21 The phage purification method was selected. 19 As a result, we have a well-crafted laboratory experiment filled with extensive experimental practice.…”

“…Biological nano-objects in aqueous systems are characterized by a surface layer that is an electric double layer. − Until recently, it was hard to imagine that bacteriophages would be well-characterized and that a method to describe their surface layer in detail would be developed. , Here it turns out that, through a classical spectrophotometric determination of p K a values, it is possible to predict the surface potential, obtain a whole series of ideas about how charges are distributed on the surface, and interpret the surface pH. − This is realized in (i) determining the p K a value of the indicator adsorbed on the surface of nanobiological species, p K a a , and (ii) calculating the surface potential using the p K a a value and the Hartley–Mukherjee–Fromherz–Funasaki equation (Figure , the step-by-step background and the protocol are also given in the Supporting Information). , Consequently, we can get important details and gain insights into “what is happening on the surface”. The proposed lab provides students with answers to the last question mentioned.…”

“…We varied several factors prior to creating this lab. , We have determined that quinaldine red, Reichardt’s dye, bromothymol blue, ethyl ester of fluorescein, β-dinitro-4- n -dodecylphenol, and n -decylester of fluorescein are not suitable for the determination of the twofold influence of MS2 bacteriophage on the p K a value. The average difference between p K a a in the MS2 bacteriophage solution and p K a in pure water was −0.21 for β-dinitrophenol, γ-dinitrophenol, and p -nitrophenol and +0.43 for neutral red, hexamethoxy red, and rhodamine .…”

“…The average difference between p K a a in the MS2 bacteriophage solution and p K a in pure water was −0.21 for β-dinitrophenol, γ-dinitrophenol, and p -nitrophenol and +0.43 for neutral red, hexamethoxy red, and rhodamine . In the PCV2 bacteriophage solution, this difference was −0.19 for γ-dinitrophenol and +0.59 for hexamethoxy red . The phage purification method was selected .…”