A procedure in which the ''Invitrogen Easy-DNA'' kit was followed by a silica-based method for the isolation of DNA was developed for extraction of PCR-inhibitor-free DNA from up to 300 mg of human vessel wall tissue. Optimally designed PCR assays were developed for the detection of at least one infected cell in this amount of tissue. Details of the procedure are given for the detection of DNA of Chlamydia pneumoniae, cytomegalovirus and herpes simplex virus type 1 and type 2 in human vessel walls. The procedure can serve as a reference method or as a gold standard when a high-performance method is needed.Une technique utilisant le kit Invitrogen Easy-DNA suivi d'une methode sur silice pour l'isolement de l'ADN a ete mise au point pour l'extraction de l'ADN depourvu d'inhibiteur PCR, a partir de 300 mg de tissu vasculaire parietal humain. Les dosages PCR doivent permettre de deceler au moins 1 cellule infectee par echantillon tissulaire. La technique est detaillee pour la detection de l'ADN de Chlamydia pneumoniae, du cytomegalovirus et des types 1 et 2 de l'herpesvirus. Et cette technique, de haute performance, peut servir de methode de reference.