A simple logic-network based lab layout. It uses logic controls on the belts to only allow a total of 50 of each type of science pack onto the belt. This is enough to keep all of the labs working but not overwhelm the belt with junk. It's not "tileable" per se, but you can put as many of these down as needed for your level of science pack production. Just remove the substations from the edge and place the next one right up against it.
Inspiration came from the Sushi Belt Science blueprint from DocMad, but this adds beacons and modules.