Physical sequestration of the origin, delay in remethylation, competition for DnaA binding, hydrolysis of DnaA- bound ATP, and repression of dnaA transcription are the key steps to regulate initiation.

#Id: 2928

#Unit 13. Methods in Biology

#Id: 2929

#Unit 13. Methods in Biology

The time of sedimentation (in seconds) for a spherical particle is (Please see the picture below)
where t is the sedimentation time, is the viscosity of medium, R hydro is the
hydrodynamic radius of the particle, r b is the radial distance from the centre of rotation
to bottom of tube, r t is the radial distance from the centre of rotation to liquid meniscus,
ρ is the density of the particle, m is the density of the medium and is the angular velocity
of the rotor.

#Id: 2984

#Unit 13. Methods in Biology

The unit of s is seconds Most values of s are between 10-13 and 10-11 second. To
eliminate the exponents, the value of s is usually reported in svedbergs (S). 1 svedberg 10-13 second.

#Id: 2987

#Unit 13. Methods in Biology

During differential sedimentation the largest class of particles forms a pellet on the
bottom of the centrifuge tube, leaving smaller-sized structures within the supernatant.

#Id: 2991

#Unit 13. Methods in Biology

Isopycnic separation, centrifugation is continued until the desired particles have
reached their isopycnic position in the liquid density gradient.

#Id: 2995

#Unit 13. Methods in Biology