A trunk of human cytidylate-phosphate-deoxyguanylate-binding protein/CXXC finger protein 1 (CFP1), immobilized onto an aminohexyl-Sepharose column, can be used as a preanalytical tool for the selective enrichment of bacterial DNA from mixed solutions with high amounts of human background DNA for nucleic acid amplification technique-based detection of pathogens. The transcriptional activator protein exhibits a high affinity for nonmethylated CpG dinucleotide motifs, which are differentially distributed in prokaryotic and higher eukaryotic genomes. The feasibility of the affinity chromatography (AC) step was tested with DNA from severely septic patients. AC using 16S rRNA gene primers substantially increased PCR sensitivity. Approximately 90% of eukaryotic DNA was removed, which significantly increased the signal-to-noise ratio. Threshold cycle values revealed that sensitivity was elevated at least 10-fold. The change in the ratio of bacterial DNA to human DNA increased from 26% to 74% the likelihood of culture-independent PCR-based identification of bacterial presence. Compared to the results seen with blood culture (which is the clinical gold standard for systemic infections, exhibiting 28% positives), the combination of AC and PCR achieves a significant increase in sensitivity and contributes to shortening the time to results for the initiation of guided antibiotic therapy.The routine methods utilized in clinical microbiology laboratories, such as the demonstration of the presence of pathogens in samples from patients suspected of systemic infections, are predominantly culture based and exhibit drawbacks due to antibiotic treatment of the patient prior to sample withdrawal (e.g., from blood, wound swabs, or cerebrospinal fluid), low abundance of causative agents in exclusive samples, and, frequently, noncultivable or growth-repressed organisms. The gold standard, blood culture (BC), for example, returns negative results for 80% to 90% of all invasive infection incidents even when the presence of an infection is obvious from the medical history and additional clinical diagnostics. Cultural results usually take periods of 24 to 72 h to be obtained, whereas a sample can be reliably declared negative within up to 7 days' incubation (26, 27). These results are therefore only the basis for further microbial diagnostics, e.g., species differentiation and/or generation of antibacterial susceptibility profiles, which are also laborious and time-consuming processes. The derivation of an antibiotic therapy from the results obtained with the gold standard (e.g., in the case of sepsis) within the first "golden hours" would determine the course and prognosis for the case (17); however, such an approach is currently not feasible, while adequate (directed) and early antibiotic therapies are mandatory for the avoidance of mortal outcomes (7,8,11,28). In the case of sepsis, an increase of mortality of 7% to 8% per hour was proven after delay of adequate antibiotic treatment (12). Moreover, the rise in the rate of infective disea...