POLYCARBONATE & POLYPROPYLENE BOTTLES    ultra

These screw top ultra bottles are a modified Oakridge design which means the top shoulder is square rather than sloped for lower stresses and longer life.  Polycarbonate bottle assemblies are provided in three common sizes for use in many fixed-angle rotors.  The three-piece cap assembly assures a liquid-tight seal during centrifugation.  To cap the bottles, place the o-ring on the underside of the plug flange and insert the plug into the neck of the bottle.  The o-ring is compressed and the seal made when the aluminum cap is hand-tightened onto the neck of the bottle.

Polycarbonate is transparent and autoclavable at 121 deg. C.  Because autoclaving significantly reduces the cycle life of polycarbonate bottles, cold sterilization is recommended.  When autoclaving, separate the cap assembly from the bottle.  Because of the thick walls, the bottle cannot be sliced or punctured.  Polycarbonate is resistant to neutral salts and dilute acid solutions but is not resistant to alkaline solutions.  It is suggested that the bottles be used at a pH below 8 to extend life.  Polypropylene has useful but limited solvent resistance at centrifugal stresses.  It has excellent resistance to alkaline gradients and can be used in a 2-12 pH range.  The useful centrifuge temperature range is 0-30 deg. C.  Polypropylene is translucent.