Forward genetics is used to identify genes that are involved in particular biological processes. For example, genes required for disease resistance can be found by identifying mutants with reduced or increased disease resistance, genes that control flower development can be identified by searching for mutants with altered flower morphology, and genes encoding enzymes for tryptophan biosynthesis can be identified by searching for mutants that require exogenous tryptophan for growth. - [Read Forward Genetics in Arabidopsis: Finding Mutations that Cause Particular Phenotypes Protocol]
FP-TDI Method for SNP Detection. The FP-TDI protocol was originally reported by Drs. Chen, Levine, and Kwok at Washington University in 19991,2. FP-TDI stands for template directed dye terminator incorporation assay with detection by fluorescence polarization. It is a single base primer extension assay couple with homogeneous FP detection. Perkin Elmer - [Read FP-TDI Method for SNP Detection]
Protocol describes a method for performing isoelectric fractionation of a maize embryo sample using a multicompartment electrolyzer(MCE). This prefractionation of proteins having pIs within a certain pH interval is essential for allowing high loads of protein to be resolved on narrow and ultra-narrow immobilized pH gradients used in 2D electrophoresis. The isoelectric membranes in the MCE act like isoelectric traps capturing all the protein species having pIs encompassing the pI value of each... - [Read Fractionation of Maize Embryo Proteins for 2-D Gel Electrophoresis Using Multicompartment Electrolyz]
Protocol describes a method for DNA fragmentation by nebulization, in which the fine mist created by forcing a DNA solution through a small hole in the nebulizer unit is collected. The size of the fragments obtained by nebulization is determined chiefly by the speed at which the DNA solution passes through the hole, altering the pressure of the gas blowing through the nebulizer, the viscosity of the solution, and the temperature. - [Read Fragmentation of DNA by Nebulization Protocol]
Protocol describes a method for DNA fragmentation by sonication. During sonication, DNA samples are subjected to hydrodynamic shearing by exposure to brief periods of sonication. DNA that has been sonicated for excessive periods of time is extremely difficult to clone. - [Read Fragmentation of DNA by Sonication Protocol]
This protocol describes a method for freezing and thawing ES cells using cryovials. It is important to freeze ES cell stocks as soon as possible to reduce the time that they are in culture. A careful record should be kept of the number of times cells are passaged and the location of the cryovials. - [Read Freezing and Thawing of Embryonic Stem (ES) Cells Using Cryovials Protocol]
This protocol provides a method for the synchronization of a monolayer culture of CHO cells in G1 using isoleucine deprivation. Since CHO cells can also be adapted to grow in suspension culture, this procedure can be used to obtain larger quantities of cells. When isoleucine is replaced, the cells resume growth and begin to enter S phase ~4 hours later. This method arrests almost 100% of the CHO cells in G1, and upon reversal, leads to rapid recovery of cell growth and very high cell viability. - [Read G1 Synchronization of CHO Cells by Isoleucine Deprivation Protocol]
This protocol provides a method for the synchronization of a monolayer culture of CHO cells in G1 using isoleucine deprivation. Since CHO cells can also be adapted to grow in suspension culture, this procedure can be used to obtain larger quantities of cells. When isoleucine is replaced, the cells resume growth and begin to enter S phase ~4 hours later. This method arrests almost 100% of the CHO cells in G1, and upon reversal, leads to rapid recovery of cell growth and very high cell viability. - [Read G1 Synchronization of CHO Cells by Isoleucine Deprivation Protocol]
This protocol provides a method for synchronizing cells at the G1/S border using a double treatment of thymidine, which, in excess, is an inhibitor of DNA synthesis. Cells are treated once with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. - [Read G1/S Phase Synchronization using Double Thymidine Synchronization Protocol]
This protocol provides a method for synchronizing cells at the G1/S border using a double treatment of thymidine, which, in excess, is an inhibitor of DNA synthesis. Cells are treated once with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. - [Read G1/S Phase Synchronization using Double Thymidine Synchronization Protocol]
This protocol provides a method for synchronizing cells at the G1/S border using a double treatment of thymidine, which, in excess, is an inhibitor of DNA synthesis. Cells are treated once with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. - [Read G1/S Phase Synchronization using Double Thymidine Synchronization Protocols]
This protocol uses the plant amino acid mimosine as a G1/S synchronizing agent. Cells are first treated with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. Thymidine is then removed to allow all the cells to proceed completely through the S phase. Mimosine is then added to arrest the cells at the G1/S border. When mimosine is removed, cells will begin to enter S phase within about 1 hour. - [Read G1/S Phase Synchronization Using Mimosine Arrest Protocol]
Protocol uses the plant amino acid mimosine as a G1/S synchronizing agent. Cells are first treated with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. Thymidine is then removed to allow all the cells to proceed completely through the S phase. Mimosine is then added to arrest the cells at the G1/S border. When mimosine is removed, cells will begin to enter S phase within about 1 hour. - [Read G1/S Phase Synchronization Using Mimosine Arrest Protocol]
This protocol uses the plant amino acid mimosine as a G1/S synchronizing agent. Cells are first treated with excess thymidine to accumulate the majority of them at G1/S; however, some cells will have stopped growth within the S phase. Thymidine is then removed to allow all the cells to proceed completely through the S phase. Mimosine is then added to arrest the cells at the G1/S border. When mimosine is removed, cells will begin to enter S phase within about 1 hour. - [Read G1/S Phase Synchronization Using Mimosine Arrest Protocol]
A crude lysate gel assay can be performed to roughly quantitate the DNA in lysates. This is often a valuable time saving step to determine if the phage yield is sufficient to warrant continuing the procedure. - [Read Gel Assay to Determine DNA Content of Phage Lysates Protocol]
Protocol exploits differences in electrophoretic mobility through a nondenaturing polyacrylamide gel between a rapidly migrating target DNA and a more slowly migrating DNA-protein complex. - [Read Gel Retardation Assays for DNA-binding Proteins Protocol]
This protocol describes a method for constant-flow microinjection using the Pneumatic PicoPump (World Precision Instruments). This type of system is very simple and can be assembled on a relatively low budget. In this method, a constant flow of sample is delivered from the tip of the pipette, and the amount of sample injected into the cell is determined by how long the pipette remains in the cell. - [Read Gene Delivery by Direct Injection (Microinjection) Using a Controlled-Flow System Protocol]
This protocol describes a method for pulsed-flow microinjection using the Eppendorf FemtoJet injector and Eppendorf InjectMan; this is the most common type of pulsed-flow microinjection system currently being used. The advantage of this type of system over a controlled-flow system is that much more control is available over the injection parameters, reducing variability in injections. In addition, the system allows a diagonal insertion of the needle into the cell. - [Read Gene Delivery by Direct Injection (Microinjection) Using a Pulsed-Flow System Protocol]
The technique has many advantages—plasmids may be used for delivery, DNA theoretically can be delivered to any cell type, and genes may be delivered to cells in vitro, ex vivo, or in vivo. DNA-coated gold particles are distributed evenly along the length of the tubing, which is subsequently cut into short sections of cartridges to be used in a gene gun. The Helios Gene Gun uses a pulse of helium to launch the DNA-coated particles, spreading them onto the target cells. - [Read Gene Delivery to Skin Using Biolistics Protocol]
Shotgun sequencing of a large segment of DNA involves random fragmentation of the target region into smaller segments that are subsequently cloned into a bacteriophage M13 vector. The goal is to create a library of overlapping clones that provide at least fivefold coverage over the entire length of the target fragment. - [Read Generation of a Library of Randomly Overlapping DNA Inserts Protocol]
In this method, the nuclease BAL 31 is used to make uni- or bidirectional deletions in a segment of cloned DNA. BAL 31 is a complex enzyme and tends to digest a population of double-stranded DNA targets in an asynchronous fashion, Deletions created by BAL 31 are therefore far more heterogeneous in size than those created by processive enzymes such as exonuclease III. - [Read Generation of Bidirectional Sets of Deletion Mutants by Digestion with BAL 31 Nuclease Protocol]
In Vitro Translated Xenopus Mos Kinase Assay Protocol. In response to progesterone, immature Xenopus oocytes mature to eggs that can be fertilized. The Mos protein kinase is essential for oocyte maturation, most likely due to its ability to activate the MAP kinase cascade. This MAP kinase cascade eventually leads to the activation of Cdc2/cyclin B and entry into M phase. In this protocol, tagged Mos kinase is translated in vitro, immunopurified, and used in a kinase assay.