Our work presents a protocol for the encapsulation and subsequent affinity isolation of the proteinaceous compartment carrying a DNA segment. To this end, we have repurposed the microcompartment of Citrobacter freundii for propaneadiol utilisation (Pdu) and constructed a LacI transcription repressor that allows the assembly of a synthetic organelle containing the LacI-DNA complex. High-throughput sequencing of extracted DNA from the affinity-isolated MCPs shows that our strategy results in leads to packaging of a DNA segment carrying multiple LacI binding sites, but not the flanking regions.