Accurate diagnosis of bacterial infection leads to appropriate patient management, providing information on prognosis and allowing the use of narrow-spectrum antibiotics. This in turn reduces side effects for the patient, saves money and may slow the spread of antibiotic resistance. Some bacterial species, however, are difficult to isolate, or grow slowly in the laboratory due to stringent growth requirements, while others may not grow due to prior empirical treatment of patients with anti-microbial agents. Molecular diagnostic techniques, such as Polymerase Chain Reaction (PCR), are being developed to aid in the diagnosis of bacterial infection by detecting bacterial genetic material. Unlike culture, most molecular assays are designed specifically for one organism. This provides high sensitivity and specificity but only detects what you are looking for; multiple assays may be required to screen for multiple organisms. Broad range assays, based on ribosomal genes (rDNA), are designed to overcome this limitation. Bacterial rDNA consists of highly conserved nucleotide sequences that are shared by all bacterial species, interspersed with variable regions that are genus or species specific. The DNA sequences of the variable regions form the basis of phylogenetic classification of microbes. By using PCR primers that are targeted at conserved regions of rDNA ,it is possible to design broad-range PCRs capable of detecting DNA from almost any bacterial species. The identity of the bacterium captured is revealed by nucleotide sequencing of the PCR product followed by comparison of this sequence with known sequences located in Genbank or other databases. Under research conditions this approach has been applied to samples from normally sterile sites to diagnose a wide raqnge of bacterial infections when culture results proved negative. We have developed a broad-range PCR, based on bacterial 16S rDNA, for use in the routine diagnostic clinical microbiology service. This PCR is performed on culture negative specimens for improved diagnosis of bacterial infection and can also be used to identify organisms growing on solid media.

Also known as

16S PCR, broad-range bacterial PCR, 16S rRNA PCR, ribosomal PCR, pan-bacterial PCR

Request a test

To request this test please send sample with a request providing patient ID (three identifiers), specimen information, assay required, relevant clinical details and sender information. Before sending sample please read details on requesting and labelling by clicking on the link. Please also refer to any additional information provided for this test.

Additional information

This test can be performed as part of a 'bacterial PCR screen' which includes real-time PCR assays for up to four specific bacterial targets for a fixed price (please enquire). The specific real-time PCRs can be selected from our repertoire or we can select the appropriate assays based on the clinical details provided and our own testing algorithm.

Sending address

Microbiology, Virology and Infection Control Level 4, Camelia Botnar Laboratories Great Ormond Street Hospital for Children Great Ormond Street London WC1N 3JH DX number: DX6640203 DX Exchange: Bloomsbury 91WC

Laboratory service

Microbiology, Virology and Infection Control

Sample requirements

Any sample from a normally sterile site. Minimum volume 200 microlitres. Isolates on slopes.

Reference range

Not applicable

Turnaround time

48 hours - 7 days

Disease / group

Bacterial infection


Upon request

Call in advance?

Not required

Microbiology, Virology and Infection Control

Our laboratory performs a wide range of routine and specialist investigations in Bacteriology, Virology and PCR.

© 2011 Great Ormond Street Hospital for Children NHS Trust