Our Single Tube Scanner is now only 495 GBP and 545 GBP with cryoprotection. Get it while it's hot: info@idquest.nl http://t.co/Dj1RfJ47
24 May 2012, 1:43 am
Our Single Tube Scanner is now only 495 GBP and 545 GBP with cryoprotection. Get it while it's hot: info@idquest.nl http://t.co/Dj1RfJ47

Our Single Tube Scanner is now only 495 GBP and 545 GBP with cryoprotection. Get it while it's hot (prices apply... http://t.co/lwTKEe2T
23 May 2012, 3:45 am
Our Single Tube Scanner is now only 495 GBP and 545 GBP with cryoprotection. Get it while it's hot (prices apply... http://t.co/lwTKEe2T

Cryobanking of Korean allium germplasm collections: results from a 10 year experience.
24 April 2012, 10:28 am
Cryobiology Cryobanking of Korean allium germplasm collections: results from a 10 year experience. - http://www.hubmed.org/display... April 24 from HubMed -... - Comment - Like Cryo Letters. 2012 Jan-Feb; 33(1): 45-57 Kim HH, Popova E, Shin DJ, Yi JY, Kim CH, Lee JS, Yoon MK, Engelmann F This paper reviews a 10-year experience in establishing a cryopreserved Allium germplasm collection at the genebank of the National Agrobiodiversity Center, Republic of Korea. A systematic approach to Allium cryopreservation included: 1. revealing the most critical factors that affected regeneration after cryostorage; 2. understanding the mechanisms of cryoprotection by analyzing the thermal behavior of explants and cryoprotectant solutions using DSC and influx/efflux of cryoprotectants using HPLC; 3. assessing genetic stability of regenerants; and 4. revealing the efficiency of cryotherapy. Bulbil primordia, i.e. asexual bulbs formed on unripe inflorescences, proved to be the most suitable material for conservation of bolting varieties due to high post-cryopreservation regrowth and lower microbial infection level, followed by apical shoot apices from single bulbs and... - Daniel Mietchen

Impact of pr-10a overexpression on the cryopreservation success of Solanum tuberosum suspension cultures.
19 January 2012, 6:46 am
Cryobiology Impact of pr-10a overexpression on the cryopreservation success of Solanum tuberosum suspension cultures. - http://www.hubmed.org/display... January 19 from HubMed - "freeze - Comment - Like Plant Cell Rep. 2012 Jan 18; Vaas LA, Marheine M, Seufert S, Schumacher HM, Kiesecker H, Heine-Dobbernack E Although many genes are supposed to be a part of plant cell tolerance mechanisms against osmotic or salt stress, their influence on tolerance towards stress during cryopreservation procedures has rarely been investigated. For instance, the overexpression of the pathogenesis-related gene 10a (pr-10a) leads to improved osmotic tolerance in a transgenic cell culture of Solanum tuberosum cv. Désirée. In this study, a cryopreservation method, consisting of osmotic pretreatment, cryoprotection with DMSO and controlled-rate freezing, was used to characterize the relation between cryopreservation success and pr-10a expression in suspension cultures of S. tuberosum wild-type cells and cells overexpressing pathogenesis-related protein 10a (Pr-10a). By varying the sorbitol concentration, thus modifying the strength of the osmotic stress during the pretreatment phase, it can be shown that... - Daniel Mietchen

Glycogen synthase kinase-3: cryoprotection and glycogen metabolism in the freeze-tolerant wood frog.
17 January 2012, 12:57 pm
Cryobiology Glycogen synthase kinase-3: cryoprotection and glycogen metabolism in the freeze-tolerant wood frog. - http://www.hubmed.org/display... January 17 from HubMed - "freeze - Comment - Like J Exp Biol. 2012 Feb 1; 215(Pt 3): 543-551 Dieni CA, Bouffard MC, Storey KB The terrestrial anuran Rana sylvatica tolerates extended periods of whole-body freezing during the winter. Freezing survival is facilitated by extensive glycogen hydrolysis and distribution of high concentrations of the cryoprotectant glucose into blood and all tissues. As glycogenesis is both an energy-expensive process and counter-productive to maintaining sustained high cryoprotectant levels, we proposed that glycogen synthase kinase-3 (GSK-3) would be activated when wood frogs froze and would phosphorylate its downstream substrates to inactivate glycogen synthesis. Western blot analysis determined that the amount of phosphorylated (inactive) GSK-3 decreased in all five tissues tested in 24 h frozen frogs compared with unfrozen controls. Total GSK-3 protein levels did not change, with the exception of heart GSK-3, indicating that post-translational modification was the primary regulatory mechanism for this... - Daniel Mietchen

cryoprotection-lyophilization and physical stabilization of rifampicin-loaded flower-like polymeric micelles.
26 August 2011, 10:00 pm
Cryobiology cryoprotection-lyophilization and physical stabilization of rifampicin-loaded flower-like polymeric micelles. - http://www.hubmed.org/display... August 26 from HubMed - "freeze - Comment - Like J R Soc Interface. 2011 Aug 24; Moretton MA, Chiappetta DA, Sosnik A Rifampicin-loaded poly(ε-caprolactone)-b-poly(ethylene glycol)-poly(ε-caprolactone) flower-like polymeric micelles display low aqueous physical stability over time and undergo substantial secondary aggregation. To improve their physical stability, the lyoprotection-lyophilization process was thoroughly characterized. The preliminary cryoprotectant performance of mono- and disaccharides (e.g. maltose, glucose), hydroxypropyl-β-cyclodextrin (HPβCD) and poly(ethylene glycol) (PEG) of different molecular weights was assessed in freeze-thawing assays at -20°C, -80°C and -196°C. The size and size distribution of the micelles at the different stages were measured by dynamic light scattering (DLS). A cryoprotectant factor (f(c)) was determined by taking the ratio between the size immediately after the addition of the cryoprotectant and the size after the preliminary freeze-thawing assay. The benefit of a synergistic... - Daniel Mietchen

The origins and evolution of freeze-etch electron microscopy.
24 August 2011, 10:35 am
Cryobiology The origins and evolution of freeze-etch electron microscopy. - http://www.hubmed.org/display... August 24 from HubMed - "freeze - Comment - Like J Electron Microsc (Tokyo). 2011; 60 Suppl 1: S3-S29 Heuser JE The introduction of the Balzers freeze-fracture machine by Moor in 1961 had a much greater impact on the advancement of electron microscopy than he could have imagined. Devised originally to circumvent the dangers of classical thin-section techniques, as well as to provide unique en face views of cell membranes, freeze-fracturing proved to be crucial for developing modern concepts of how biological membranes are organized and proved that membranes are bilayers of lipids within which proteins float and self-assemble. Later, when freeze-fracturing was combined with methods for freezing cells that avoided the fixation and cryoprotection steps that Moor still had to use to prepare the samples for his original invention, it became a means for capturing membrane dynamics on the millisecond time-scale, thus allowing a deeper understanding of the functions of biological membranes in living cells as well as their static... - Daniel Mietchen

Arbutin's suppression of cryodamage in goat sperm and its mechanism of cryoprotection.
2 May 2011, 1:11 pm
Cryobiology Arbutin's suppression of cryodamage in goat sperm and its mechanism of cryoprotection. - http://www.hubmed.org/display... May 2, 2011 from HubMed - "freeze - Comment - Like Theriogenology. 2011 Apr 27; Aboagla EM, Maeda T Arbutin (4-hydroxyphenyl-glucopyranoside) is a glycosylated hydroquinone present in high concentrations in the leaves of several plants capable of surviving prolonged, extreme dehydration. Two experiments were conducted to determine the effects of arbutin on cryopreservation of goat sperm. In Experiment 1, goat sperm were frozen in extenders with various ratios of Tris-citric acid-glucose (TCG) and arbutin; concentrations of the latter were 0.0 (only TCG), 0.1, 0.2, 0.3, and 0.4 M (only arbutin)]. All extenders had 20% (v/v) egg yolk (EY) and 4% (v/v) glycerol (osmolality = 370 mOsm, pH = 7.0). Sperm motility and acrosome integrity were assessed using CASA, and fluorescein isothiocyanate-labeled peanut agglutinin (FITC-PNA), respectively. Percentages of motile and progressively motile sperm improved with the addition of arbutin; results were optimal (89.0 and 70.0%, respectively; P < 0.05), with 0.4 M arbutin. Furthermore, arbutin... - Daniel Mietchen

Cryogenic and low temperature preservation of human placental villous explants - A new way to explore drugs in pregnancy disorders.
25 January 2011, 5:20 am
Cryobiology Cryogenic and low temperature preservation of human placental villous explants - A new way to explore drugs in pregnancy disorders. - http://www.hubmed.org/display... January 25, 2011 from HubMed - "freeze - Comment - Like Placenta. 2011 Feb; 32S1: S65-S76 Huppertz B, Kivity V, Sammar M, Grimpel Y, Leepaz N, Orendi K, Pekarski I, Meiri H, Gonen R, Lubzens E BACKGROUND: A major handicap in cell culture studies using human tissues is the insufficient availability of fresh material on site. A method was developed for cryogenic storage and low temperature preservation of human placental villous explants, facilitating multi-site distribution for functional studies. METHODS: Explants from term placentas were incubated with cryoprotectant agents (dimethyl-sulfoxide (DMSO), ethylene glycol, propanediol or Aedesta), frozen in liquid nitrogen, thawed and then cultured in-vitro. Viability was assessed by comparing frozen and thawed explants with non-frozen controls for morphological changes, lactate dehydrogenase (LDH) release, placenta protein 13 (PP13) secretion, and PCNA Western blotting. Functional studies determined the effect of oxygen and magnesium on explant viability. RESULTS: cryoprotection by 3 M DMSO... - Daniel Mietchen

A molecular mechanism of solvent cryoprotection in aqueous DMSO solutions.
5 January 2011, 4:56 am
Cryobiology A molecular mechanism of solvent cryoprotection in aqueous DMSO solutions. - http://www.hubmed.org/display... January 5, 2011 from HubMed - "freeze - Comment - Like Phys Chem Chem Phys. 2011 Jan 5; Mandumpal JB, Kreck CA, Mancera RL Dimethyl sulfoxide (DMSO) in aqueous solution is widely used for the preservation of biological tissues under freezing conditions. DMSO and other agents are believed to act colligatively to depress the freezing point of water and, importantly, to promote the vitrification of water to prevent its crystallisation and the ensuing damage arising from the formation of intracellular ice. However, there has been no direct evidence of the precise effect of these agents on the vitrification properties of water. Here we report direct computational evidence, using molecular dynamics annealing simulations carried out within the experimentally inaccessible region in supercooled water, of a broadening of the glass transition of water, corresponding to the formation of a stronger glass in aqueous DMSO solutions. These findings provide insight at the molecular level into the mechanism of solvent cryoprotection by suggesting that the... - Daniel Mietchen