The effects of buffer salt concentration on the HPLC retention of nucleic acid components

1989 ◽  
Vol 28 (9-10) ◽  
pp. 493-496 ◽  
Author(s):  
Guanghui Liu
1946 ◽  
Vol 30 (2) ◽  
pp. 101-116 ◽  
Author(s):  
A. W. Pollister ◽  
A. E. Mirsky

The nucleoprotamine of trout sperm can be extracted completely with 1 M sodium chloride. On reducing the salt concentration to 0.14 M, physiological saline, the nucleoprotamine precipitates in long, fibrous strands. When the nucleoprotamine, dissolved in M NaCl, is dialyzed all the protamine diffuses through the membrane leaving behind highly polymerized, protein-free desoxyribose nucleic acid. The nucleoprotamine constitutes 91 per cent of the lipid-free mass of the sperm nucleus. While nucleoprotamine is being extracted by M NaCl a stage is reached at which the sperm chromosomes are clearly visible.


2021 ◽  
Author(s):  
Reece W. Lewis ◽  
Benjamin Klemm ◽  
Mariano Macchione ◽  
Rienk Eelkema

Triggered coacervate phase (de)stabilisation in complex coacervate core micelles (C3Ms) has traditionally been limited to changes in pH and salt concentration, limiting options in responsive C3M material design. To expand this toolbox, we have developed C3Ms, that, at constant physiological pH, assemble and disassemble by coupling to a chemical reaction network (CRN) driven by the conversion of electron deficient allyl acetates and thiol or amine nucleophiles. This CRN produces transient quaternization of tertiary amine-functionalised block copolymers, which can then form the complex coacervate phase. We demonstrate triggered C3M assembly using two different allyl acetates, resulting in dramatically different assembly rates from hours to days. These are applied in various combinations with selected nucleophiles, demonstrating sequential signal induced C3M formation and deformation, as well as transient non-equilibrium (de)formation. We expect that timed and signal-responsive control over coacervate phase formation at physiological pH will find application in nucleic acid delivery, nano reactors and protocell research.


2016 ◽  
Vol 23 (03) ◽  
pp. 1650014 ◽  
Author(s):  
Z. MAKHDOUMI KAKHAKI ◽  
A. YOUZBASHI ◽  
P. SANGPOUR ◽  
A. KAZEMZADEH ◽  
N. NADERI ◽  
...  

Effects of buffer salt concentration on the rate of deposition, dominated deposition mechanism and subsequently the structural, morphological, and optical properties of cadmium sulfide (CdS) thin films deposited by chemical bath deposition (CBD) on glass substrate were investigated. The precursors were chosen to be cadmium chloride (CdCl2) as the cadmium source, thiourea (CS(NH[Formula: see text]) as the sulfur source, ammonium nitrate (NH4NO3) as the buffer salt and ammonia as the complexing agent and the pH controller. The influence of the NH4NO3 concentration on the structure, morphology, film uniformity, stoichiometry and optical properties of CdS thin films was also studied by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectroscope, uv–visible and photoluminescence (PL) spectroscopes. The XRD studies revealed that all the deposited films exhibited a (002)h/(111)c preferred orientation. The crystallite size was increased from 20[Formula: see text]nm to 30[Formula: see text]nm by the increase of concentration of NH4NO3 from 0.5[Formula: see text]M to 2.5[Formula: see text]M. The morphology of CdS thin films were agglomerated spherical particles consisted of smaller particles. The surface of thin films deposited at the NH4NO3 concentration of 0.5[Formula: see text]M was compact and smooth. The increase of the concentration of NH4NO3 decreased the packing density of the films. The optical band gap was in the range of 2.25–2.4[Formula: see text]eV, which was decreased by the decrement of packing density. The PL spectra showed two peaks centered at 400[Formula: see text]nm and 500[Formula: see text]nm which are attributed to violet and band-to-band emissions, respectively.


2021 ◽  
Author(s):  
Reece W. Lewis ◽  
Benjamin Klemm ◽  
Mariano Macchione ◽  
Rienk Eelkema

Triggered coacervate phase (de)stabilisation in complex coacervate core micelles (C3Ms) has traditionally been limited to changes in pH and salt concentration, limiting options in responsive C3M material design. To expand this toolbox, we have developed C3Ms, that, at constant physiological pH, assemble and disassemble by coupling to a chemical reaction network (CRN) driven by the conversion of electron deficient allyl acetates and thiol or amine nucleophiles. This CRN produces transient quaternization of tertiary amine-functionalised block copolymers, which can then form the complex coacervate phase. We demonstrate triggered C3M assembly using two different allyl acetates, resulting in dramatically different assembly rates from hours to days. These are applied in various combinations with selected nucleophiles, demonstrating sequential signal induced C3M formation and deformation, as well as transient non-equilibrium (de)formation. We expect that timed and signal-responsive control over coacervate phase formation at physiological pH will find application in nucleic acid delivery, nano reactors and protocell research.


Author(s):  
W. Bernard

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.


Sign in / Sign up

Export Citation Format

Share Document