Biosensor Technology

The Ibis T5000™ Biosensor System technology relies on the use of broad-range primers to amplify highly conserved genomic regions that flank sequences with variable information content. The primers are designed to amplify a product from a group of organisms from a selected domain of microbial life such as all bacteria or specific bacterial divisions. To prepare a sample, nucleic acids are extracted and dispensed into wells of a microtiter plate. Each well contains one or more pairs of broad-range primers for PCR amplification.

PCR products are then desalted and introduced into a mass spectrometer. Mass spectrometry is exquisitely sensitive, enabling the system to determine the base composition from small quantities of nucleic acids in a complex mixture. By evaluating weights to determine the base compositions of complementary DNA strands from multiple sequences and algorithmically comparing this information to proprietary databases, the Ibis system was designed to rapidly and automatically identify pathogens with high accuracy and at high throughput.

Representation of the "base composition" space.

The Ibis T5000 Biosensor System determines a base composition for each pathogen. In this example, B. anthracis, with a base composition of A(34) G(31) C(29) T(27), is clearly distinguished from numerous other closely related bacterial species.