Run Times - Beckman Coulter J-Lite JLA 16.250 Instruction Manual

J-Lite JLA-16.250 Rotor

RUN TIMES

18
Thickwall Tubes
Thickwall polypropylene and polycarbonate tubes can be run partially
filled (at least half filled) with or without caps, but all opposing tubes
for a run must be filled to the same level with liquid of the same den-
sity. Do not overfill capless tubes; be sure to note the fill volumes and
run speeds shown in Table 3.
Polycarbonate and Polypropylene Bottles
Capped polycarbonate and polypropylene bottles may be centrifuged
completely or partially filled (not less than half full). Again, all
opposing containers for a run must be filled to the same level.
The k factor is a measure of a rotor's pelleting efficiency. Beckman
Coulter has calculated the k factor for all of its rotors, at maximum
speed with full bottles or tubes, using the following formula:
k =
Where ω is the angular velocity of the rotor in radians per second
(ω = 0.105 × rpm), r
max
minimum radius.
After substitution:
(
2.533
k = ------------------------------------------------------------------------- -
Use the k factor in the following equation to estimate the run time t
(in hours) required to pellet particles of known sedimentation coeffi-
cient s (in Svedberg units, S).
13
( ⁄ )
ln r r
10
max min
×
------------------------------------ - ----------- -
2 3600
ω
is the maximum radius, and r
11
× ) ( r ⁄
10 ln r
max min
2
rpm
(1)
is the
min
)
(2)