In this protocol, bacterial cells are lysed by being subjected to short, intense treatments with ultrasound, which breaks the cell walls and shears the DNA into sizes that will not affect the viscosity of the samples. Note that this method causes some denaturation of the samples. The resulting lysate is ready for preclearing. - [Read Immunoprecipitation: Lysing Bacteria by Sonication Protocol]
GFP serves as a molecular marker that can be imaged dynamically in living cells, both in its native form & as a fusion to other proteins. For GFP imaging, plants present the challenge of autofluorescence from chlorophyll, lignified cell walls, vacuolar contents, and other cell materials, all of which can obscure the GFP signal. Maximizing the signal-to-noise ratio is a major concern, and careful consideration should be given to the choice of tissue imaged, GFP expression level, etc. - [Read Live-Cell Imaging of GFP in Plants]
Protocol for preparation of DNA for pulsed-field gel electrophoresis: isolation of intact DNA from yeast. Yeast cells are first treated enzymatically to break down the cell walls and then resuspended in low-melting-temperature agarose plugs. The DNA is liberated by infusing the plugs with lysis buffer and proteases. This method is used to prepare both conventional and artificial yeast chromosomes. - [Read Preparation of DNA for Pulsed-field Gel Electrophoresis: Isolation of Intact DNA from Yeast]
Although Percoll gradients were able to provide a purified sporocyst fraction, because these particles do not all band in a discrete manner in such gradients, they were unable to provide a simultaneous isolation of a pure oocyst wall fraction. Gradients formed from this protocol on the other hand are able to provide purified sporocysts and oocyst walls in the same gradient. - [Read Purification of Oocyst Walls and Sporocysts from Toxoplasma gondii Protocol]