This protocol describes a sealed preparation that allows the continuous long-term observation of cultured mammalian cells on upright or inverted microscopes without environmental CO2 control. The preparation allows for optical conditions consistent with high-quality imaging and good cell viability for at least 100 hours. - [Read A Sealed Preparation for Long-Term Observations of Cultured Cells]
Adapted from Frommer et.al. Good protocol for bisulfite treatment of DNA. Includes tips on Methylation PCR for CpG methylation analysis. University of Texas M. D. Anderson Cancer Center - [Read Bisulfite Treatment of DNA for Methylation Analysis]
This CGH Protocol is used for DNA of good quality when available in sufficient amounts. We usually do replicate hybridizations using samples labeled "inversely" (reversing the label for test and normal DNA's). If appreciable artifact occurs, then alternative labels are tried. - [Read CGH of Direct Labeled Test DNA vs Normal DNA Protocol]
Chemotaxis Practical. Thierry Soldati. Department of Biological Sciences Animal and Plant Physiology. The assay in brief. Safety and Good Laboratory Practice: Working in a Cell Biology Laboratory. I-Chemotaxis Assay. Observation of Dictyostelium development stages. - [Read Chemotaxis Practical]
Cytostatic factor extract (CSF) preparation for spindle assembly protocol. Protocol includes tips such as: The quality of the eggs is essential for good CSF extracts. Always sacrifice quantity for quality when trying to make functional extracts. - [Read Cytostatic Factor (CSF) Extract Preparation for Spindle Assembly Protocol]
Protocol for cytostatic factor extract preparation for spindle assembly. The quality of the eggs is essential for good CSF extracts. Always sacrifice quantity for quality when trying to make functional extracts. Discard any batches of eggs that have "puff balls" or activated eggs that constitute more than 10% of the eggs. Use laid eggs and collect eggs at about 16 to 17 hours after priming with Progesterone (found in Pregnant Mare Serum Gonadotropin (PMSG)). - [Read Cytostatic Factor (CSF) Extract Preparation for Xenopus Spindle Assembly Protocol]
Allows students to easily isolate chromosomal DNA from onion cells using the same basic tools and methods that scientists use in the lab. A good introduction to using pipettes. Kate Dollard - [Read DNA Isolation from Onion Cells]
Bouin’s fixative is a particularly good choice for worms because it penetrates dense tissues well and is extremely good for fixing antigens. Like all strong fixatives, however, it is unsuitable for some antibody-antigen pairs. In such cases, the length of time in the Bouin’s fixative can be shortened, or paraformaldehyde fixation can be used instead. - [Read Fixing Caenorhabditis elegans in Bouin’s Fixative Protocol]
Common method for fixing worms is to use paraformaldehyde. This method provides a gentler fixation than the Bouin’s method, but often requires the use of collagenase. This method is particularly good for examining adult worms. - [Read Fixing Caenorhabditis elegans in Paraformaldehyde Protocol]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope]
In recent years, the increased sensitivity of electron detectors and the availability of low-vacuum or variable-pressure systems have allowed imaging of fresh tissue samples without the need for fixation, drying, and coating. This obviously saves a lot of time, although the image quality may not be as good as that obtained from fixed samples. However, for most applications that tend to be at a relatively low magnification, the quality can be as good as that obtained from fixed samples. - [Read Imaging of Fresh Arabidopsis Tissues in the Scanning Electron Microscope Protocol]
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]
Direct labeling of purified antibodies is the method of choice when simultaneously visualizing two or more antibodies of the same species, class, or subclass. This allows the localization of multiple antigens to be compared in the same cell, tissue, or sample. Labeled primary antibodies are also useful for improving background-to-readout ratios, and they can be essential for immunoassays in which good quantification is needed. - [Read Labeling Antibodies with Fluorochromes Protocol]
Protocol describes a plate method that gives very good yield for cloning. Includes: T-TYN Media + Mg+2; T-TYN Plates; T-TYN Top Agarose. - [Read Lambda DNA Preparation Protocol]
Confocal laser scanning microscopy (CLSM) is a relatively new light microscopical imaging technique which has found wide applications in the biological sciences. The primary value of the CLSM to the biologist is its ability to produce optical sections through a 3-D specimen-e.g., an entire cell or a piece of tissue - that, to a good approximation, contain information from only one focal plane. Article includes principle and applications of confocal laser scanning microscope. - [Read Looking Inside Cells and Tissues by Optical Sectioning with a Confocal Laser Scanning Microscope]
Paraformaldehyde Fixation of Cells protocol. This fixation method is good for cells labeled by fluorochrome-conjugated antibodies to membrane antigens. It will stabilize the light scatter and labeling for up to a week in most instances, allowing you to be more flexible in scheduling cytometer time. Furthermore, it inactivates most biohazardous agents, so it is important from a safety standpoint as well. Iowa University. - [Read Paraformaldehyde Fixation of Cells]
An ideal method of tissue preparation ensures both good specimen morphology and that the target molecules are in the optimum state for probe access and hybridization. DNA:DNA in situ hybridization is usually carried out on chromosome spread preparations where chromosome and nuclei are released from cells and spread on a glass microscope slide. This method yields well separated and enlarged chromosomes with good morphology which can be analyzed in transmitted light or fluorescence microscopes. - [Read Preparation of Chromosome Spreads]
Frozen tissue sections show good preservation of tissue structure and antigens. The principle disadvantages of using them in immunostaining are that the specimens must be stored frozen, and a special microtome, known as a cryostat, is required. Also, many clinical specimens are not available in this form, and most classic histological descriptions of tissue structure and pathology are based on the use of paraffin-embedded sections of formalin-fixed material. - [Read Preparing Frozen Tissue Sections for Immunostaining Protocol]
Coimmunoprecipitation is one of the most useful techniques for revealing protein-protein interactions. Good negative controls to verify the specificity of the coimmunoprecipitation procedure are (1) performing the same immunoprecipitation experiment using beads coupled to the preimmune serum and (2) probing the Western blot with antibodies against protein known not to interact with the coimmunoprecipitated proteins under physiological conditions. - [Read Protein Coimmunoprecipitation in Arabidopsis Protocol]
Riboprobe® in vitro Transcription Systems Promega. For the in vitro synthesis of RNA. For large quantities of RNA, use Ribomax very good kit. - [Read Riboprobe in vitro Transcription 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.