Centrifugal method and apparatus for isolating a substance from a

Abstract

A centrifugal rotor effects the isolation, in a sequence of steps, of a substance from a mixture of substances dissolved, suspended or dispersed in a sample liquid. Multiple samples are processed simultaneously by means of a plurality of fractionation cells, each of which contains a series of interconnected, chambered and vented compartments in which individual steps of the fractionation and isolation procedure take place. Specific steps in the preferred embodiments include lysis, sedimentation, aggregation, sorption, rinsing, and desorption. The specific compartment occupied by the sample liquid or one of its fractions at any stage of the process is governed by the speed and direction of rotation of the rotor and by gravitational force. The interconnections, chambers and passages of each compartment are sized and angled to prevent predetermined amounts of sample and reagent liquids from overflowing the compartment. Predetermined amounts of the reagent liquids required to contact the sample in individual steps of the isolation process are simultaneously delivered to specific compartments of every cell by means of a dynamic flow distributor which accepts partially aerosolized injections of said reagents pipetted from a dosator while the centrifugal rotor is rotating. A method of using the rotor to isolate deoxyribonucleic acid is described. The operation of the centrifuge and the dosator can be controlled and coordinated automatically.