calf thymus depolymerized ds dna (Millipore)
Structured Review
![Schematic diagram of the formation of liquid-crystalline dispersion as a result of phase exclusion of linear ds <t>DNA</t> <t>molecules</t> <t>[molecular</t> mass (6–8) × 105 Da)] from PEG-containing water-salt solutions. 1. Initial ds DNA molecules in a PEG-containing solution (PEG molecules are shown by filled red circles) at CPEG below the critical value. 2. Particle of the DNA liquid-crystalline dispersion (encircled by an oval) formed at CPEG above the critical value. (P is the pitch of the helical twist of the spatial structure of a dispersion particle.) 3. A quasinematic layer formed by ds DNA molecules (the cross at the center denotes the rotation axis of the helical structure). [Note that DNA molecules in a quasinematic layer are located at a distance, which changes from 2.5 to 5.0 nm depending on the osmotic pressure of the solution (thick red frame and dark arrows are symbols of osmotic pressure of a PEG-containing solution)]](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_3345/pmc05323345/pmc05323345__10867_2016_9433_Fig1_HTML.jpg)
Calf Thymus Depolymerized Ds Dna, supplied by Millipore, used in various techniques. Bioz Stars score: 90/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
https://www.bioz.com/product/dna+depolymerization/calf+thymus+depolymerized+ds+dna/pmc05323345-99-0-5
Average 90 stars, based on 1 article reviews
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1) Product Images from "Re-entrant cholesteric phase in DNA liquid-crystalline dispersion particles"
Article Title: Re-entrant cholesteric phase in DNA liquid-crystalline dispersion particles
Journal: Journal of Biological Physics
doi: 10.1007/s10867-016-9433-4
Figure Legend Snippet: Schematic diagram of the formation of liquid-crystalline dispersion as a result of phase exclusion of linear ds DNA molecules [molecular mass (6–8) × 105 Da)] from PEG-containing water-salt solutions. 1. Initial ds DNA molecules in a PEG-containing solution (PEG molecules are shown by filled red circles) at CPEG below the critical value. 2. Particle of the DNA liquid-crystalline dispersion (encircled by an oval) formed at CPEG above the critical value. (P is the pitch of the helical twist of the spatial structure of a dispersion particle.) 3. A quasinematic layer formed by ds DNA molecules (the cross at the center denotes the rotation axis of the helical structure). [Note that DNA molecules in a quasinematic layer are located at a distance, which changes from 2.5 to 5.0 nm depending on the osmotic pressure of the solution (thick red frame and dark arrows are symbols of osmotic pressure of a PEG-containing solution)]
Techniques Used:
Figure Legend Snippet: Experimental small-angle X-ray scattering curves from the phase formed via low-speed sedimentation of DNA LCD particles measured at four different temperatures. 1–20 °C, 2–40 °C, 3–60 °C, 4–80 °C. Conditions of DNA LCD particle formation: CDNA = 30 μg ml−1, CPEG = 300 mg ml−1, 0.3 M NaCl + 0.002 M Na+ phosphate buffer; T = 20 °C
Techniques Used: Sedimentation
Figure Legend Snippet: Experimental small-angle X-ray scattering curves from phases formed via low-speed sedimentation of DNA LCD particles. Conditions of DNA LCD particle formation: 1 - CPEG = 170 mg ml−1, 2 - CPEG = 300 mg ml−1. CDNA = 30 μg ml−1; 0.3 M NaCl + 0.002 M Na+ phosphate buffer. Inset: the dependence of the mean distance between DNA molecules (d) in liquid crystalline phases upon PEG concentration. a Experimental curves of small-angle X-ray scattering by liquid-crystalline phases formed via low-speed sedimentation of DNA LCD particles. b Fingerprint texture typical of the DNA classical cholesteric liquid-crystalline phase. CPEG = 170 mg ml−1; 0.3 M NaCl + 0.002 M Na+ phosphate buffer. Bar corresponds to 5 μm
Techniques Used: Sedimentation, Concentration Assay
Figure Legend Snippet: a Dependence of the amplitude of the abnormal band in the CD spectra of DNA LCDs (λ = 270 nm) formed in water-salt solutions (0.3 M NaCl + 0.002 M Na+ phosphate buffer) with different PEG concentrations on the temperature. 1 - CPEG = 220 mg ml−1, 2 - CPEG = 240 mg ml−1, 3 - CPEG = 260 mg ml−1, 4 - CPEG = 280 mg ml−1, 5 - CPEG = 300 mg ml−1. CDNA = 30 μg/ml. ΔA270 × 10−6 optical units; L = 1 cm. Arrows show the mean values of transition temperature (τtrans.) of DNA LCDs from the optically inactive to optically active state for two different condition sets. b Dependence of the value τtrans. versus PEG concentration. Different points relate to two series of independent experiments
Techniques Used: Concentration Assay
Figure Legend Snippet: Dependence of the amplitude of the abnormal band (λ = 270 nm) in the CD spectra of DNA LCDs formed at room temperature (curve 1), heated to 80 °C (curve 2) and cooled to room temperature (curve 3) on PEG concentration. CDNA = 30 μg ml−1, 0.3 M NaCl + 0.002 M Na+ phosphate buffer. ΔA270 × 10−6 optical units; L = 1 cm. Symbols I and II correspond to various PEG domains; arrows show the direction of the CD band amplitude change at temperature increase
Techniques Used: Concentration Assay
Figure Legend Snippet: CD spectra of DNA LCD treated with SYBR Green (curves 2–5), measured at different temperatures. 2–22 °C, 3–40 °C, 4–80 °C, 5–80 °C → 22 °C. CDNA = 30 μg ml−1, CPEG = 250 mg ml−1, 0.3 M NaCl + 0.002 M Na+ phosphate buffer. CSG = 0.781 × 10−5 M. 1 – the CD spectrum of the initial DNA LCD (22 °C, control). ΔA = (AL – AR) × 10−6 optical units, L = 1 cm
Techniques Used: SYBR Green Assay
Figure Legend Snippet: Hypothetical scheme of hexagonal ds DNA molecule packing in dispersion particles formed in PEG-containing solution. (Dark spots are PEG-molecules outside closely packed DNA molecules) (See text above this Fig.)
Techniques Used:
Figure Legend Snippet: Theoretically computed CD spectra of ds DNA cholesteric LCD particles: curve 1 – CD spectrum for classical ds DNA cholesteric LCD (d = 3.5 nm, P = 2,500 nm, φ = 0.5°); curve 2 – CD spectrum for model artificial ds DNA cholesteric LCD (d = 2.5 nm, φ = 0.5°); curve 3 - CD spectrum for model artificial ds DNA cholesteric LCD (d = 2.5 nm, φ = 1.0°); curve 4 - CD spectrum for model artificial ds DNA cholesteric LCD (d = 2.5 nm, φ = 1.5°). D = 550 nm, CDNA = 30 μg ml−1, ΔA = (AL – AR) × 10−6 optical units, L = 1 cm. φ - the twist angle between neighboring quasinematic layers
Techniques Used:
Figure Legend Snippet: Theoretically calculated dependence of the abnormal negative band amplitude (∆A 270) upon the pitches (P) of hypothetical ds DNA cholesterics. Point 1 (green) corresponds to the real parameters of ds DNA classical cholesteric. Point 2 (red) corresponds to the P value that is equal to about 500 nm. CDNA = 30 μg ml−1, ΔA270 × 10−6 optical units, L = 1 cm
Techniques Used: