Abstract: An instrument for determination of the base sequence of deoxyribonucleic acid (DNA) which is designed to dectect DNA fragments in course of gel electrophoresis in real time to determine the base sequence of DNA, and comprises a gel electrophoretic panel part wherein DNA fragments labeled with a radioisotope are supplied to four places in a gel for four kinds of complementary strand synthesis reaction systems, respectively, and subjected to electrophoresis to form an electrophoretic pattern of the DNA fragments, and a detection part for detecting the electrophoretic pattern of the DNA fragments provided at a predetermined position in said gel electrophoretic panel part so as to have a position resolving power in a direction perpendicular to the direction of electrophoretic migration of the DNA fragments, and which instrument has a means for making the temperature of the gel in the vicinity of the detection part for detecting the electrophoretic pattern of the DNA fragments higher than that on the DNA fragment

Abstract: An electrophoretic apparatus according to this invention comprises electrophoretic paths along which sample fragments labeled with phosphor migrate; electrodes disposed at both the ends of said electrophoretic paths; a driving power source for giving said sample fragments on the electrophoretic paths electrophoretic force by applying an electric potential difference between said electrodes; an excitation light source projecting an excitation light to said sample fragments on said electrophoretic paths; and means for detecting fluorescence emitted by the phosphor existing in the sample fragments and excited by the excitation light. Said an excitation light source is so disposed that the excitation light is projected to said sample fragments on said electrophoretic paths in a direction substantially parallel to a plane containing said electrophoretic paths.

Abstract: An improved electrophoresis apparatus for nucleic acid fragments in which nucleic acid fragments are separated in the order of their molecular weight in an electrophoresis cell using an electrophoretic gel for determining the base sequence of a nucleic acid, the improvement comprising a nucleic acid fragment specimen supply section for supplying the nucleic acid fragments to the electrophoresis cell, disposed thereover a molecular sieving membrane having a predetermined degree of molecular permeability for separating to remove those high molecular weight ingredients in the nucleic acid fragment specimen other than the fragments intended to be analyzed electrophoretically.