Solvent partition protocol allows the isolation of gangliosides from small samples and from samples where ganglioside concentrations are low, especially relative to the concentration of potentially contaminating proteins and other large molecular weight species. Stephan Ladisch Director, Center for Cancer and Transplant Biology, Children's National Medical Center, Washington, D.C. - [Read A Method for Micro-Scale Isolation and Purification of Gangliosides]
Protocol describes how to construct a library of 35-45-kb fragments of genomic DNA in the double cos site cosmid vector, SuperCos-1. The steps include: Linearization and dephosphorylation of SuperCos-1 DNA; Partial digestion of high-molecular-weight DNA with MboI; Dephosphorylation of high-molecular-weight genomic DNA; Ligation of cosmid arms to genomic DNA: Packaging and plating recombinants; Isolation and analysis of recombinant cosmids: Validation of the library. - [Read Construction of Genomic DNA Libraries in Cosmid Vectors Protocol]
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]
Protocol describes methods for isolation of DNA from a strain of S. cerevisiae carrying a recombinant YAC. Because the linear YAC DNAs are sensitive to shearing forces, pipettes with wide-bore tips should be used to transfer DNAs. The method is suitable for preparing DNA that will be used for agarose gel electrophoresis, Southern blotting, subcloning, genomic library construction, PCR, or other methods that do not require intact high-molecular-weight DNA. - [Read Growth of S. cerevisiae and Preparation of DNA Protocol]
Protocol that isolates intact, high molecular weight DNA from yeast cells for subcloning and rare cutting restriction enzyme analysis. Using this protocol one can expect a yield of 100-200 µg of DNA per prep. - [Read High Molecular Weight Yeast Liquid DNA Preparation Protocol]
Protocol describes how to assay for kinase activity within a polyacrylamide gel, rather than in solution. The advantages to an in-gel assay are that an apparent molecular weight can be assigned to the kinase activity and that multiple kinase activities can be distinguished. Includes protocol hints. - [Read In-Gel Kinase Assay]
Method of choice when large amounts of mammalian DNA are required, for example, for Southern blotting (Rapid Isolation of Mammalian DNA, Rapid Isolation of Yeast DNA, Southern Blotting: Capillary Transfer of DNA to Membranes) or for construction of genomic libraries in bacteriophage {lambda} vectors. Approximately 200 µg of mammalian DNA, 100-150 kb in length, is obtained from 5 x 107 cultured aneuploid mammalian cells (e.g., HeLa cells). - [Read Isolation of High-molecular-weight DNA from Mammalian Cells Using Proteinase K and Phenol Protocol]
Following propagation to 1 X 108 cells, lymphoblastoid cells are conveniently stored at -80 degrees C to preserve the high molecular weight DNA in the cells until the DNA is purified. This procedure describes the steps required to harvest and freeze the c - [Read Method: Preparation of Lymphocyte Cell Pellet for Storage]
RNA-RNA in situ hybridization using DIG-labeled probes: the effect of high molecular weight polyvinyl alcohol on the alkaline phosphatase indoxyl-nitroblue tetrazolium reaction. RNA-RNA in situ hybridization protocol using alkaline phosphatase-conjugated digoxigenin-(DIG-) labeled probes is presented. The addition of polyvinyl alcohol (PVA) of high molecular weight (40 – 100 kD) to the BCIP-NBT detection system enhances the alkaline phosphatase reaction and prevents... - [Read RNA-RNA In Situ Hybridization Using DIG-Labeled Probes Protocol]
Protocol used to determine the position of molecular-weight markers and to ensure that efficient transfer of proteins to the blot has occurred, the total composition of the proteins can be determined by staining the membrane with Ponceau S (Staining Immunoblots for Total Protein Using Ponceau S) or India ink. - [Read Staining Immunoblots for Total Protein Using India Ink Protocol]
Protocol used to determine the position of molecular-weight markers and to ensure that efficient transfer of proteins to the blot has occurred, the total composition of the proteins can be determined by staining the membrane with Ponceau S . - [Read Staining Immunoblots for Total Protein Using Ponceau S Protocol]
Unlike spherical phage, such as T4 and λ, which have roughly equal weight ratios of protein to DNA, filamentous phage have about six times more protein than DNA; the protein therefore contributes substantially to the absorption spectrum.