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.

Abstract: A method for sequencing DNA by hybridization that includes the following steps: forming an array of oligonucleotides at such concentrations that either ensure the same dissociation temperature for all fully complementary duplexes or allows hybridization and washing of such duplexes to be conducted at the same temperature; hybridizing said oligonucleotide array with labeled test DNA; washing in duplex dissociation conditions; identifying single-base substitutions in the test DNA by analyzing the distribution of the dissociation temperatures and reconstructing the DNA nucleotide sequence based on the above analysis. A device for carrying out the method comprises a solid substrate and a matrix rigidly bound to the substrate. The matrix contains the oligonucleotide array and consists of a multiplicity of gel portions. Each gel portion contains one oligonucleotide of desired length. The gel portions are separated from one another by interstices and have a thickness not exceeding 30 .mu.m.