The names assigned to each strand actually depend on which direction you are writing the sequence that contains the information for proteins (the "sense" information), not on which strand is depicted as "on the top" or "on the bottom" (which is arbitrary). The only biological information that is important for labeling strands is the relative locations of the terminal 5′ phosphate group and the terminal 3′ hydroxyl group (at the ends of the strand or sequence in question), because these ends determine the direction of transcription and translation. A sequence written 5′-CGCTAT-3′ is equivalent to a sequence written 3′-TATCGC-5′ as long as the 5′ and 3′ ends are noted. If the ends are not labeled, convention is to assume that both sequences are written in the 5′-to-3′ direction. The "Watson strand" refers to 5′-to-3′ top strand (5′→3′), whereas the "Crick strand" refers to the 5′-to-3′ bottom strand (3′←5′). Both Watson and Crick strands can be either sense or antisense strands depending on the specific gene product made from them.