This Craig recrystallization tube is a combination crystallizing and filtration centrifuge tube. Filtered solutions are allowed to cool in the Craig tube, inducing crystallization. The Craig stopper is placed in the tube neck and the whole apparatus is inverted into a test or centrifuge tube. Centrifuging forms a mat of crystals between the stopper and the walls of the Craig tube, and draws away excess solvent. Further washing and crystallization steps are possible. Two are required to balance in a centrifuge. Tube Capacity: 4mL. Height: 80mm. Tube O.D.: 14mm. Kimble Chase #: 283550-0004.