Organic solvents such as alcohols and acetone remove lipids and dehydrate cells, precipitating the proteins on the cellular architecture. Be aware that different antigens may be affected differently by the various solvents. If no previous data are available for your antigen, start with the 50/50 mixture. For tissue culture dishes, concentrations of acetone higher than 50% will destroy the integrity of the plastic. - [Read Fixing Attached Cells in Organic Solvents Protocol]
Gram-positive and Gram-negative organisms form a complex of crystal violet and iodine within the bacterial cell during the Gram-staining procedure. Gm+ organisms are thought to resist decolorization by alcohol or acetone because cell wall permeability is markedly decreased when it is dehydrated by these solvents. Thus, the dye complex is entrapped within the cell, resist being washed out by the solvents, and Gm+ bacteria remain purple following this differential stain. - [Read Gram Staining Protocol]
Hybridization is carried out in conventional aqueous solvents at a temperature well below the predicted melting temperature. Nonspecific hybrids are then removed by washing at high stringency in buffers containing quaternary salts. Tetramethylammonium chloride (TMACl) is used with probes that are 14-50 nucleotides in length, whereas tetraethylammonium chloride (TEACl) is used with longer oligonucleotides. - [Read Hybridization of Oligonucleotide Probes in Aqueous Solutions Protocol]
Early embryos (0-17 hours or until cuticle formation) are treated with a mixture of organic solvents, formaldehyde, and alcohols, as described here. The cuticles of late-stage embryos are usually opened by sonication. Tissues from more advanced stages of development are normally dissected by hand and then fixed and stained in a standard paraformaldehyde/detergent combination - [Read Preparing Early Whole-Mount Drosophila Embryos for Immunostaining Protocol]
Early and late embryos are treated with a mixture of organic solvents, formaldehyde, and alcohols. The cuticles of late-stage embryos (17-22 hours or until hatching) are usually opened by sonication, as described here. Tissues from later stages of development are normally dissected by hand and then fixed and stained in a standard paraformaldehyde/detergent combination. - [Read Preparing Late Whole-Mount Drosophila Embryos for Immunostaining Protocol]
Protocol describes the standard method for nucleic acid purification by extraction first with phenol:chloroform (optionally containing hydroxyquiniline at 0.1%) and then with chloroform to remove any remaining phenol. The procedure takes advantage of the fact that deproteinization is more efficient when two different organic solvents are used instead of one. - [Read Purification of Nucleic Acids by Extraction with Phenol:Chloroform Protocol]