Micro sample tubes/cryovials with screw caps are essential lab consumables designed for secure storage and handling of small liquid or solid samples. These tubes feature leak-proof screw caps, ensuring sample integrity during cryogenic storage (-80°C to -196°C), centrifugation, or transport. Common materials include polypropylene (PP) for chemical resistance and autoclavability. Key variations include: 1) **Low-retention tubes** – ideal for precious samples; 2) **Sterile/pre-sterilized tubes** – for cell culture; 3) **Color-coded caps** – easy sample identification; 4) **Graduated scales** – volume measurement. Typical capacities range from 0.5mL to 5mL. Applications span PCR sample prep, biobanking, and chemical reagent storage. Industry standards may include DIN/ISO certifications and DNase/RNase-free guarantees.