scholarly journals Standard Bacteriophage Purification Procedures Cause Loss in Numbers and Activity

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 328
Author(s):  
Amanda Carroll-Portillo ◽  
Cristina N. Coffman ◽  
Matthew G. Varga ◽  
Joe Alcock ◽  
Sudha B. Singh ◽  
...  

For decades, bacteriophage purification has followed structured protocols focused on generating high concentrations of phage in manageable volumes. As research moves toward understanding complex phage populations, purification needs have shifted to maximize the amount of phage while maintaining diversity and activity. The effects of standard phage purification procedures such as polyethylene glycol (PEG) precipitation and cesium chloride (CsCl) density gradients on both diversity and activity of a phage population are not known. We have examined the effects of PEG precipitation and CsCl density gradients on a number of known phage (M13, T4, and ΦX 174) of varying structure and size, individually and as mixed sample. Measurement of phage numbers and activity throughout the purification process was performed. We demonstrate that these methods, used routinely to generate “pure” phage samples, are in fact detrimental to retention of phage number and activity; even more so in mixed phage samples. As such, minimal amounts of processing are recommended to introduce less bias and maintain more of a phage population.

1979 ◽  
Vol 36 (1) ◽  
pp. 61-72
Author(s):  
S. Knutton

Freeze-fracture electron microscopy has been used to investigate the mechanism of polyethylene glycol-induced cell fusion. Interaction of cells with the high concentrations of polyethylene glycol required for cell fusion results in cell agglutination with large planar areas of very close contact between adjacent cell membranes. An aggregation of intramembrane particles into large patches at the sites of cell-cell contact accompanies cell agglutination. Fusion occurs following the removal of most of the PEG when cells only remain in close contact at small (approximately 0.1 micrometer diameter) plaques of smooth membrane resulting in cells connected by one (or more) small cytoplasmic connexions. Expansion to form spherical fused cells occurs by a process of cell swelling.


RSC Advances ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 2435-2442 ◽  
Author(s):  
Bing-Liang Ma ◽  
Yan Yang ◽  
Yan Dai ◽  
Qiao Li ◽  
Ge Lin ◽  
...  

High concentrations of PEG400 increase in vivo exposure to berberine (D) by increasing its solubility (A), permeability (B), and lymphatic transport (C).


1977 ◽  
Vol 25 (5) ◽  
pp. 371-375 ◽  
Author(s):  
P Kjellstrand

The polymer polyethylene glycol combined with hydrochloric acid was used during the hydrolysis stage of the Feulgen method in order to limit the movement of the soluble molecular fragments developed through hydrolytic breakdown of the deoxyribonucleic acid. The diffusion of the purines was not influenced by the addition of concentration of the polymer up to 30%. On the other hand, a substantial retardation of the extraction of deoxyribonucleic acid and apurinic acid was noted. This indicates that deoxyribonucleic acid and apurinic acid are extracted in chains of considerable length. The decrease in diffusion rate was greater at 1 M HCl than at 0.3 and 6 M HCl, which indicates that the deoxyribonucleic acid-apurinic acid fragments are larger at the medium concentration of acid than at the low and high concentrations. The results thus strengthen the view that deoxyribonucleic acid and apurinic acid are extracted in chains during hydrolysis, and that the critical length at which the chains becomes diffusible is one of the main factors determining the form of the Feulgen hydrolysis curve. The use of polyethylene glycol to extend the maximum of the hydrolysis curve, and thus to make the temperature and time of hydrolysis less critical, is recommended.


Biochemistry ◽  
1976 ◽  
Vol 15 (9) ◽  
pp. 1865-1873 ◽  
Author(s):  
Thomas R. Cech ◽  
Gary Wiesehahn ◽  
John E. Hearst

1991 ◽  
Vol 81 (3) ◽  
pp. 289-295 ◽  
Author(s):  
C. J. Lote ◽  
H. Saunders

INTRODUCTION: SOURCES AND BIOAVAILABILITY OF ALUMINIUM Aluminium is the most abundant metal and constitutes 8% of the earth's crust. It is a normal constituent of vegetable and animal tissues and is present in raw untreated water. In domestic tap-water supplies, aluminium may be present in high concentrations either from its presence in raw water or, more commonly, as a result of its use during the water-purification process. Aluminium in the metallic form is widely used for both industrial and domestic purposes, and a variety of aluminium salts are used in foods, fluids, cosmetics and medications. The toxicity of aluminium in patients with renal failure is now well documented, and dialysis encephalopathy, osteomalacia and anaemia are recognized hazards in such patients if aluminium is not excluded from dialysis fluids and medications. The safe levels of aluminium in food, water, medications and infusion fluids for subjects with normal renal function are unknown, but aluminium has been implicated as causative agent in a number of dementia diseases, including Alzheimer's disease.


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