Using AFPredictor, it was demonstrated that ‘ordered surface carbons’ (OSCs) are a distinguishing feature of AFPs and, more specifically, their ice-binding surfaces. AFPredictor identified AFPs from within a large set of structures with greater than 99% specificity. Furthermore, it was used to identify a novel ice-binding protein by screening a library of homology modeled structures based on cDNA sequences obtained from cold-acclimated winter rye (Secale cereale). - [Read A Computational Screening protocol for Antifreeze/Ice-Structuring Proteins]
The protocol presented in this Application Sheet uses an alternative strategy to sedimentation on to a density barrier, that is to adjust the density of whole blood to a value just greater than the cells of interest and allow them to float to the surface. - [Read C8 Isolation of bovine peripheral blood mononuclear cells by flotation.]
Polybrene and DMSO can be used to achieve stable transformation of several types of cells by plasmid DNA. The yield of transformants is up to 15-fold greater with Polybrene than with calcium phosphate-DNA coprecipitation. However, there is no difference between the two methods in the efficiency of transformation of cells by high-molecular-weight DNA. - [Read DNA Transfection Using Polybrene Protocol]
Most biological specimens are relatively transparent, so details of internal and intracellular morphology are difficult to image in untreated living specimens using simple bright-field techniques. Fluorescence microscopy offers greater advantages and possibilities for increasing contrast and determining the specific localization of molecules in cells. Article outlines the three methods most commonly used to introduce an appropriate label into Drosophila tissue without perturbing the process. - [Read Fluorescent Reagents for Live Cell Imaging and Their Introduction into Cells]
Mature Tetrahymena cells of opposite mating types are starved under appropriate salt conditions. The mating types are then combined to costimulate through cell-cell interaction. Loose pairs and then firm, irreversible pairs of cells of opposite mating types form. This method consistently results in a high percentage of pairing (usually greater than 80%) and good synchrony. - [Read Induction of Conjugation in Tetrahymena Protocol]
A solution containing plasmid DNA, saturating amounts of ethidium bromide, and CsCl (44% w/v) is layered between two solutions of lesser (35% w/v CsCl) and greater density (59% w/v CsCl). During centrifugation to equilibrium, the closed circular plasmid DNA and linear DNAs form bands at different densities. - [Read Purification of Closed Circular DNA by Equilibrium Centrifugation in CsCl-Ethidium Bromide Gradient]
Rapid Elution of DNA Agarose Gels Protocol. This method allows quick purification of DNA fragments from agarose gels for use in cloning and other reactions. Higher yields of purified DNA can be obtained from commercially available purification kits, however greater ligation efficiencies per given amount of DNA have been seen with the use of these described spin columns. Hahn Lab. - [Read Rapid Elution of DNA Agarose Gels Protocol]
Protargol-S (silver proteinate) is used with the addition of copper metal. The copper replaces the silver in the connective tissue, allowing a greater differentiation between the nerve fibers and the connective tissue. The silver is reduced with hydroquinone to the visible metallic form. The sections are toned with gold chloride, the gold chloride is reduced with oxalic acid, increasing the deposit of metallic gold on the sections. - [Read Staining of Nerve Fibers Protocol]
This protocol describes the electroporation of the BMH 81-17 mut S strain that is recommended for tranformation of the site directed mutagenesis of dsDNA (See Protocol on Site-Directed Mutagenesis on Double Stranded DNA). BMH 81-17 mut S are a mismatch repair defective (mut S) Escherichia coli strain. The probability that the two mutations will cosegregate during the first round of DNA replication is increased in this strain.