Transcription-Mediated Amplification

Innovative technology simplifies NAT; speeds workflow

PROCLEIX® Assays, such as the PROCLEIX® HIV-1/HCV Assay, use Transcription-mediated Amplification (TMA) technology to simplify NAT by enabling simultaneous detection of multiple viruses in a single tube. TMA technology allows your lab to perform NAT assays for blood screening with fewer steps and less processing time for faster results. Fewer material transfer steps also means less risk of contamination.

State-of-the-art TMA technology was developed by Gen-Probe, Chiron's partner for NAT innovation.

Target Capture

Samples are prepared for testing by lysing the viruses to release the genetic material -- no pretreatment or handling is required. Capture probes hybridize internal control (IC) and viral nucleic acids and bind them to magnetic particles. Unbound material is washed away to remove non-specific material and to minimize potential inhibitors.

Amplification

Transcription-mediated amplification (TMA) is used to amplify portions of the RNA and/or DNA. Reverse transcriptase creates a DNA copy (cDNA) of the target nucleic acid. RNA polymerase initiates transcription, synthesizing RNA. Some of the newly synthesized RNA amplification products reenter the TMA process and serve as templates for new rounds of amplification. Potentially billions of copies are generated in less than one hour.1

Detection

Acridinium ester (AE)-labeled probes specifically hybridize to the amplification products. Different AE variants are used to label the IC- and viral-specific probes. The hybridization protection assay (HPA) process selectively inactivates the AE label on unhybridized probes to minimize background signal. Dual kinetic assay (DKA) technology enables simultaneous detection of both IC-encoded RNA by producing a flash of light, and viral-encoded RNA by producing a longer-lasting glow.

PROCLEIX is a trademark of Novartis Vaccines and Diagnostics.
 

References

  1. F Gonzales and S McDonough. Applications of Transcription-Mediated Amplification to Quantification of Gene Sequences. Gene Amplification. 1998 Ed. François Ferre, Birkhauser, Boston. PP. 189-204.