Chromatographic purification method for the isolation of a desired product fraction from a mixture using 2 chromatographic columns (1,2) by sequential loading, wherein the method comprises, within one cycle to be carried out at least once, the following steps: a first batch step, wherein during a batch timespan (t B) said columns are disconnected and a first column is loaded with feed via its inlet using a first flow rate (Q feed,B) and its outlet is directed to waste, and from a second column thereof desired product is recovered via its outlet and subsequently the second column is regenerated, with the proviso that if this first batch step is carried out for the first time, said second column is either idle or preceding the first batch step an interconnected startup step is carried out, in which the second column is loaded with feed; a first interconnected step, wherein the outlet of the first column is connected to the inlet of the second column during an interconnected timespan (t IC), the first column is loaded beyond its dynamic breakthrough capacity with feed via its inlet using a second flow rate (Q feed,IC) which is the same or larger than the first flow rate (Q feed,B), and the outlet of the second column is directed to waste, and wherein during a subsequent washing timespan (t wash,IC) which is larger or equal to 0 s the outlet of the first column is connected to the inlet of the second column, the first column is loaded with solvent and/or buffer which is free from feed material, and the outlet of the second column is directed to waste, a second batch step analogous to the first batch step but with exchanged column positions, such that the first column of the first batch step performs the tasks of the second column of the first batch step, and the second column of the first batch step performs the tasks of the first column of the first batch step; a second interconnected step, analogous to the first interconnected step but with exchanged column positions, such that the upstream column of the first interconnected step is the downstream column of the second interconnected step, and the downstream column of the first interconnected step is the upstream column of the second interconnected step. a first batch step, wherein during a batch timespan (t B) said columns are disconnected and a first column is loaded with feed via its inlet using a first flow rate (Q feed,B) and its outlet is directed to waste, and from a second column thereof desired product is recovered via its outlet and subsequently the second column is regenerated, with the proviso that if this first batch step is carried out for the first time, said second column is either idle or preceding the first batch step an interconnected startup step is carried out, in which the second column is loaded with feed; a first column is loaded with feed via its inlet using a first flow rate (Q feed,B) and its outlet is directed to waste, and from a second column thereof desired product is recovered via its outlet and subsequently the second column is regenerated, with the proviso that if this first batch step is carried out for the first time, said second column is either idle or preceding the first batch step an interconnected startup step is carried out, in which the second column is loaded with feed; a first interconnected step, wherein the outlet of the first column is connected to the inlet of the second column during an interconnected timespan (t IC), the first column is loaded beyond its dynamic breakthrough capacity with feed via its inlet using a second flow rate (Q feed,IC) which is the same or larger than the first flow rate (Q feed,B), and the outlet of the second column is directed to waste, and wherein during a subsequent washing timespan (t wash,IC) which is larger or equal to 0 s the outlet of the first column is connected to the inlet of the second column, the first column is loaded with solvent and/or buffer which is free from feed material, and the outlet of the second column is directed to waste, the first column is loaded beyond its dynamic breakthrough capacity with feed via its inlet using a second flow rate (Q feed,IC) which is the same or larger than the first flow rate (Q feed,B), and the outlet of the second column is directed to waste, and wherein during a subsequent washing timespan (t wash,IC) which is larger or equal to 0 s the outlet of the first column is connected to the inlet of the second column, the first column is loaded with solvent and/or buffer which is free from feed material, and the outlet of the second column is directed to waste, a second batch step analogous to the first batch step but with exchanged column positions, such that the first column of the first batch step performs the tasks of the second column of the first batch step, and the second column of the first batch step performs the tasks of the first column of the first batch step; a second interconnected step, analogous to the first interconnected step but with exchanged column positions, such that the upstream column of the first interconnected step is the downstream column of the second interconnected step, and the downstream column of the first interconnected step is the upstream column of the second interconnected step.