Stochastic model of adsorption of particles on macromolecules at an arbitrary filling

The theory of adsorption of particles on macromolecules is considered. The theory is based on the notion that the adsorption is a discrete Markovian process. In the context of this theory the average number and the variance of the number of ligands adsorbed on macromolecules are calculated exactly. The results are compared with the frequently used approximation where the number of adsorbed particles is smaller than that in the solution. It is shown that for small values of the equilibrium constant the exact and approximate values coincide practically.