Abstract: The invention relates to a method for extracting lipopolysaccharide (LPS) from rough trough mutant bacteria cells by extracting the cells with an aqueous aliphatic alcohol having from 1 to 4 carbon atoms at a temperature between 35 and 65 degrees C. to produce cells having a reduced phospholipid content. The resultant cells are then extracted with chloroform/methanol to yield LPS.

Abstract: Herein is disclosed a method for producing lipopolysaccharide (LPS), comprising: (a) growing a culture of a deep rough mutant bacterial strain in a medium; (b) maintaining the culture in stationary phase for at least about 5 hr; (c) harvesting, cells from the culture; and (d) extracting LPS from the cells. The method allows for the production of an LPS which can be used to produce a 3-O-deacylated monophosphoryl lipid A (3D-MLA) having at least about 20 mol % of the hexaacyl congener group.

Abstract: A composition for sealing porous subterranean formations comprises a mixture of a water-swellable clay and a water insoluble, water absorbent, water-swellable polymer, wherein the mixture is coated with a material that is resistant to penetration by water. The water penetration resistant material helps the delay the onset of swelling of the clay and polymer until it reaches the formations intended for sealing. Mixing the clay with the water-swellable polymer prior to coating assists in coating of the water-swellable polymer with the water penetration resistant material. The coated mixture can be suspended in an aqueous liquid, and then pumped into a subterranean cavity to seal porous formations therein.

Abstract: A composition for sealing porous subterranean formations comprises a mixture of a water-swellable clay and a water insoluble, water absorbent, water-swellable polymer, wherein the mixture is coated with a material that is resistant to penetration by water. The water penetration resistant material helps the delay the onset of swelling of the clay and polymer until it reaches the formations intended for sealing. Mixing the clay with the water-swellable polymer prior to coating assists in coating of the water-swellable polymer with the water penetration resistant material. The coated mixture can be suspended in an aqueous liquid, and then pumped into a subterranean cavity to seal porous formations therein.

Abstract: Herein is disclosed a method for producing lipopolysaccharide (LPS), comprising: (a) growing a culture of a deep rough mutant bacterial strain in a medium; (b) maintaining the culture in stationary phase for at least about 5 hr; (c) harvesting cells from the culture; and (d) extracting LPS from the cells. The method allows for the production of an LPS which can be used to produce a 3-O-deacylated monophosphoryl lipid A (3D-MLA) having at least about 20 mol % of the hexaacyl congener group.

Abstract: Novel derivatives of monophosphoryl lipid A and a process for their preparation are provided. The derivatives contain one or more free groups, such as an amine, on a side chain attached to the primary hydroxyl groups of the monophosphoryl lipid A nucleus through an ester group. The derivatives provide a convenient method for coupling the lipid A through coupling agents to various biologically active materials, substrates, and the like, wherein the immunostimulant properties of lipid A are desired.

Abstract: Modified lipopolysaccharides, particularly de-3-0-acylated monophosphoryl lipid A and de-3-0-acylated diphosphoryl lipid A, are provided by an alkaline hydrolysis under controlled conditions which removes only the .beta.-hydroxymyristic acyl residue that is ester-linked to the reducing-end glucosamine at position 3. The modified products are less endotoxic and maintain their antigenic and immuno-stimulating properties.