110 the entire assembly 100 is preferably used in conjunction with an electrophoresis device such as the ipgphor electrophoresis unit hoefer pharmacia biotech inc san francisco calif the electrophoresis device used in conjunction with the present invention preferably includes power transfer means such as power supply contact pads 190 a 190 b as shown in fig1 a the gel strip holder 140 preferably comprises contiguous upstanding side walls 170 a 170 d arranged in a substantially rectangular shape to form a frame 170 with a longitudinal length u201c l u201d at one end of the frame 170 the walls 170 a 170 d are more preferably arranged to form a slight point which visibly distinguishes the end of the gel strip holder 140 which should contact an anodic power supply contact pad 190 a from the more blunt end that should contact a cathodic power supply contact pad 190 b the frame 170 also has a bottom 170 e which is contiguous to all the upstanding walls 170 a 170 d such that the walls 170 a 170 d and floor 170 e of the frame 170 form a liquid tight container in one preferred embodiment the gel strip holder 140 preferably has electrode contact surface pairs 150 151 on the longitudinal sides of the gel strip holder frame 170 electrode contact surface 150 151 is on both sides of the gel strip holder 140 only one side shown as shown in fig1 a there are preferably two electrode contact surface pairs 150 151 with a non.