Ster
iliz
ation
Autoclaving
115
℃
（
0.7kg/cm
2
）
30minutes
O
O
O
121
℃
（
1.0kg/cm
2
）
20
minutes
X
O
O
126
℃
（
1.4kg/cm
2
）
15
minutes
X
X
X
Boiling
15 to 30 minutes
O
O
O
Ultraviolet
sterilization
200-300nm
X
X
X
Gas
sterilization
Ethylene oxide
O
X
O
Formaldehyde
O
O
O
PA: Polyallomer
；
PC
：
Polycarbonate
；
PP
：
Polypropylene
11.2.2 Cleaning PC tubes
PC materials are low in chemical resistance against alkaline solutions. Avoid using neutral detergents
with pH higher than 9. Note that pH of some neutral detergents are still higher than 9 even if diluted
according to the instruction in the maker
’
s catalog. Use detergent with its pH between 7 and 9.
11.2.3 Autoclaving PA
、
PC and PP tubes
PA begins softening at about 120
℃
, PC and PP at about 130
℃
. Autoclave PA tubes at 115
℃
（
0.7kg/cm
2
）
for 30 minutes and PC and PP tubes at 121
℃
（
0.1kg/cm
2
）
for 20 minutes. If a
certain temperature is exceeded, the tubes may be deformed.
When using a sterilizing chamber, please operate as follows:
（
1
）
Place tubes in vertical position, mouths upward. If tubes are placed sideways, they may
deform into an oval shape due to gravity.
（
2
）
Remove screw nuts and inner covers to prevent from deformation or rupture.
（
3
）
Wait until the sterilizing chamber cools down to the room temperature before the tubes
are removed.
11.2.4 Condition and life expectancy of tubes
The life expectancy of plastic tubes depends on the characteristics of samples, speed of the rotor
used, and temperature applied, and so on. When the plastic tubes are used for centrifuge of
ordinary aqueous samples (pH between 5 and 9), their life expectancies are defined as follows.
Be operated at the maximum speed:
High quality tubes (PA
、
PC
、
PP): 30-50 operations
Ordinary tubes (PA
、
PC
、
PP): around 10 operations
（
Using in low speed can extend the tube
life
）
.
Life expectancy of tubes also depends on the pretreatment conditions such as cleaning and
sterilization, lifetime can be cut down.
