Simple and universally applicable methods for staining fixed cells are presented, as are methods that utilize detergents and proteolytic treatment to permeabilize cells. Additionally, supravital cell staining with Hoechst 33342, which is primarily used for sorting live cells for subsequent culturing based on DNA-content differences, is also described. Also presented are methods for staining of cell nuclei isolated from paraffin-embedded tissues, and deconvolution of DNA-content-frequency... - [Read Analysis of Cellular DNA Content by Flow Cytometry Protocol]
The bradford dye-binding assay is a colorimetric assay for measuring total protein concentration. It involves the binding of Coomassie Brilliant blue to protein. There is no interference from cations nor from carbohydrates such as sucrose.
Detergents such as sodium dodecyl sulfate and triton x-100 can interfere with the assay, as well as strongly alkaline solutions.
Includes a general overview of the procedure and preparation of the standards in the protocol. - [Read Bradford Assay Method]
For cells grown in tissue culture, the most useful method of lysis is treating with detergents, as described in this protocol. Non-ionic detergents, such as NP-40, solubilize the plasma and intracellular membranes, break many weak intermolecular bonds, and solubilize most of the commonly studied protein antigens. RIPA lysis buffer may be used as a more rigorous extraction buffer to release all but the insoluble proteins of the cell and to break most weak noncovalent interactions. - [Read Lysing Tissue-Culture Cells for Immunoprecipitation Protocol]