Polyclear thermoplastic is transparent and non-wettable in an uncoated state.
The UltraCote layer applied to Polyclear tubes provides a wettable surface for convenient gradient formation. Thin wall Polyclear tubes are puncturable but generally with more effort than polyallomer tubes. UltraThin tubes made of the Polyclear material are about one-half the side wall thickness of open-top Polyclear tubes and are significantly easier to puncture. See UltraThin Tubes page. The useful centrifuge temperature range is 0-20°C. Polyclear tubes can be used at temperatures greater than 20°C, i.e. 25°C, but they may be difficult to extract from the rotor.
You may have to wait for up to 5 minutes to smoothly extract the tubes. The ability to extract depends on the length of run, temperature, fluid and rotor. Generally, the longer, warmer and faster the run, the greater the required effort to extract the tubes. However, at temperatures up to 20°C, the effort will not be significant. Polyclear tubes are stiffer than polyallomer and rarely collapse. In fact, you need not be as concerned about minimum fill levels as with all other tube materials. The chemical resistance of Polyclear is not as good as polyallomer, and resistance to solvents at centrifuge stresses is poor.
Mineral and paraffin oil overlays shoud be avoided as they may cause significant crazing during the run. Polyclear can be used up to a pH of 8.5. Generally the longer and warmer the run, the greater the effect of gradient pH. Sterilization can be achieved by treatment with ethylene oxide gas or by cold methods (1).
(1) Aqueous solutions of 70% ethanol, 70% isopropanol or 10% hydrogen peroxide. *Trademark of Beckman Instruments, Inc.