Sterile. AlumaSeal II is a soft non-permeable aluminum foil with a strong, medical-grade acrylic adhesive. Easy-to-pierce for direct sample recovery. Has less tendency to roll back on itself when removing the backing paper. Certified DNase- & RNase- free. Excellent chemical resistance (e.g. DMSO). Easily pierceable with single or multichannel pipettors and robotic probes. 1.4mil conformable aluminum foil allows visual verification of the seal’s security around each well.