Immuno tubes are often used for determining hormone levels, for example TSH (thyroid stimulating hormone). With a length of 75 mm and a diameter of 12 mm with and without a "star", they are available in both MICROLON® 200 and MICROLON® 600 quality. The so-called "star" at the bottom of the tubes serves to increase the surface and thus makes it possible to bind larger amounts of antigens or antibodies.