Abstract: A method for increasing the intensity of the excitation light, and thereby the sensitivity, of flow cytometers. The initial part of the signal produced by each cell as it enters the excitation focus triggers a current pulse to the excitation light source, with a duration approximately similar to the time required for the cell to pass through the focus. This current pulse, which is superimposed on the constant operating current to the light source, causes an increase of the intensity of the excitation light during the period when the cell is passing through the excitation focus and thereby an increase of the sensitivity of the flow cytometer.

Abstract: A method and device are provided for separating magnetized particles from biological fluids. Cells such as cancer cells coated with magnetized particles can be separated from uncoated healthy cells. A fluid mixture of cancer cells, healthy cells and magnetizable particles is introduced into a container such as a disposable blood bag which is attached in a cassette on an underlying plane magnetic plane that provides a magnetic field. Incubation is carried out during which the cancer cells become coated with the magnetizable particles. The magnetic field pulls the coated cells down towards the bottom of the bag and anchors them, and uncoated healthy cells are removed from the bag. The separated uncoated healthy cells may be advanced through a final separation unit where any loose magnetizable particles are removed. There is provided means for adjusting vertical distance between the cassette and the magnetic plane and for agitating fluid within the container attached to the cassette.

Abstract: Wood can be rendered fire resistant by impregnating the wood with a solution of a monomer, such as a phenol, and a fire-inhibiting salt, drying the wood and thereafter treating the wood with a solution of a second monomer, such as formaldehyde, polymerizable with the first monomer. Heating to dryness causes polymerization of the monomers. The fire resistant properties of wood treated this way are not affected by exposure to moisture. Prior to the first impregnation, after the first impregnation and after treatment with the second monomer the wood being treated is dried to a moisture content below about 4%.