Vitrex capillary tubes for blood gas analyses are made from heavy walled glass, suitable for 2.3 mm Ø adaptors. The uniform heparinisation, careful fire polishing, heavy walled tubes and robust end-caps secure proper function and reduce operating risk. Vitrex Blood Gas Tubes are also available in plastic with sodium heparin in the same sizes as Vitrex Blood Gas Tubes in glass. The plastic tube provides the same effect as the glass tube, but the possibility of contamination with the plastic tube is reduced due to breakage with no compromise in accuracy.