MOTION OF LARGE DNA-MOLECULES TRAVELING FROM SOLUTION TO GEL UNDER STEADY FIELD

Direct observation of individual T4 DNA molecules at the interface bet ween gel and pure solvent under steady electric field was carried out with fluorescence microscopy. Statistical analyses of the image data s how that (1) when a DNA arrives at the gel surface, it remains there f or a short time before the DNA stretches its arms to enter the gel, an d (2) the time spent on the gel surface increases with an increase of the agarose persentage in the gel. (C) 1996 John Wiley & Sons, Inc.