Free flow electrophoresis of a nematode C. elegans DNA was carried out on the space shuttle flight STS65/Colombia. During the processes of the experiment, the house keeping data of the FFEU and the electrophoretic migration profiles were monitored at POCC (Payload Operations Control Center) of MSFC (Marshall Space Flight Center, Alabama) according to the real-time down-link system. The three dimensional electropherogram (3DEP) on the basis of the down-linked data showed some trouble with the apparatus but three sequential experiments indicated this disturbance of the apparatus is rather preferably stable. Comparing post-flight analyses of the DNA component fractionated, that is, amplification by PCR method, it revealed that the DNAs were separated approximately into two peaks: one of them contained seven-fold higher content of DNA estimated by a
sod-4 gene probe than an
unc-6 gene probe. These results suggested that this separation technique could be still more effective for the separation of biological macromolecules such as DNA, and the efficiency of separation of the free flow electrophoresis under microgravity environment was useful.