If you have ever wanted to use multi-channel pipettors with 1.5-2.0 ml Eppendorf tubes as reservoirs, you have probably found that few tube racks are compatible with the 9 mm spacing of most multichannel pipettes. We designed this tube rack to have 18 mm spacing so that you can fill every other tip on a multi-channel pipette. This not only can be helpful for working with alternating rows of a 96-well plate, but the 18 mm spacing is also compatible with 24-well plates!