Gradient gels exponential

Johnson et al. [186] measured diffusion of fluorescein-labeled macromolecules in agarose gels. Their data agreed well with Eq. (85), which combined the hydrodynamic effects with the steric hindrance factors. Gibbs and Johnson [131] measured diffusion of proteins and smaller molecules in polyacrylamide gels using pulsed-field gradient NMR methods and found their data to fit the stretched exponential form... 

The phenomenological concept described above allows to find the partition function Q(P) = (cg/cs)flow of the flow-equilibrium by means of a perturbation calculus applied to Eq. (3 b) the reversible partition function K(P) = cjcs in Eq. (3 b) is replaced by Q(P) Q(P) is set equal to K(P) multiplied by an exponential factor containing the free enthalpy of deformation of the coils transported from the sol into the gel through the gel front, where a strong and steep velocity gradient of the column liquid deforms the coil chain with this a new non-linear integrated transport equation... 

Fig. 10.19. Gel electrophoresis in 1.8-15% exponential acrylamide gradients of total nucleolar RNA of HeLa cells. Inset is expansion of the high-concentration end of the pattern (Mirault and Scherrer 1971).

Fig. 10.20. RNA from nucleoli and from isolated preribosomes. HeLa cells were labeled for 30 min with ( H)uridine (1 Ci/ml, 2 /iM uridine, 2 x 10 cells/ml) and fractionated to obtain nucleoli. A) shows the pattern of the nucleolar RNA B) pattern of the RNA released from the isolated preribosomes. Electrophoresis on 2-6% polyacrylamide exponential gel. gradients (15 hr at 10 V/cm). ----------------------------absorbance at 260 nm ---------, H-radioactivity (Mirault and Scherrer, 1971).

The parameters required to create a 10-line exponential gradient of 0.2%, 1 nM NGF at the explant using incremental deposition of the volume of chemotropic factor onto the collagen gel, when the concentration of the stock remains constant in the microdispenser... 

It is also possible to cast polyacrylamide gels with a gradient in pore size. This gradient can either be linear or exponential. Pore size gradients can be achieved by continuously changing the monomer concentration whilst casting the gel. 

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