Coated cardboard freezer box for storing 5mL screw-cap conical centrifuge tubes in ULT freezers or LN2 systems. These cardboard cryoboxes features numbered grid lines inside and outside the box as well as an attached hinged lid which makes it impossible to confuse the orientation of the freezer box and samples. These cardboard freezer boxes have a 6 x 6 grid to hold a maximum of thirty-six 5mL screw-cap tubes. A version for 5mL snap-cap 5mL tubes is available which holds up to 25 tubes in a 5 x 5 grid format. These cardboard freezer boxes for 5mL screw-cap tubes are made from recycled material and have drainage slots on the sides (not bottom) of the boxes to allow liquid nitrogen to exit the box. Each cardboard freezer box for 5mL screw-cap tubes measures 5.25 x 5.25 x 3 inches and will fit all common 3 inch tall freezer rack slots Packaged in packs of 5 cardboard freezer boxes.