Styrolite
Styrolite is a hard, transparent substance occasionally used in medicine to secure highly contagious or infectious specimens for transport when Quarantine Fields alone are insufficient. The specimen is placed in suspended animation and encased in a skin-tight contoured layer of styrolite. Once encased, the specimen is effectively isolated from the surrounding environment. Styrolite is often used in conjunction with quarantine force fields as an added measure of redundancy.
During her time aboard the Enterprise, Doctor Katherine Pulaski used Styrolite to transport a genetically engineered Human male aboard the ship for examination. With the assistance of Chief Miles O'Brien, a site-to-site transport protocol was implemented wherein the styrolite materialized slightly ahead of the patient, thus ensuring consistent quarantine. In addition to this precaution, a level 10 quarantine field was employed until integrity of the styrolite was confirmed. (TNG: "Unnatural Selection")