Matching PVC racks grip test tubes firmly, yet allow for easy insertion and removal. Multipurpose racks will float in melted dry ice, dry ice/alcohol slurry, and water baths. Available with pre-bored holes in straight lines or as blank racks to custom configure, adding design flexibility. Rack with small holes (4410/11) holds thirty-six 1.5mL microcentrifuge tubes. Rack with large holes (4430/11) holds twenty-four 15mL conical-bottom or 13mL round-bottom tubes. All racks are 4-3/8" x 9-3/4" x 3/8". Racks are available in black, green, purple, red, and yellow.