Overview

TRAC (Transcript Analysis with the aid of Affinity Capture) is the flagship technology platform of Plexpress.  It is a novel method of high-content gene expression analysis employing multiplex detection of gene transcripts of interest (up to 30-60 genes per well in 96-well plates) simultaneously from a large number of samples. TRAC measures mRNA directly from cell lysate and does not require mRNA extraction or PCR amplification. The method is flexible, efficient, precise, and fast, and enables the use of automation technologies for high throughput, unattended operations.

This makes TRAC an ideal technology to fill the gap between studying genome-wide expressions in a small number of samples and studying a few genes in a larger number of samples; and, in so doing TRAC makes practical experiments to explore gene function more deeply and across many “states” of the biological systems under investigation such as stage of disease, impact of being perturbed by drug candidates, and pathways for toxicology and other system functions.

Crude cell lysates can be used directly as samples. Simultaneous treatment of 96 samples has been automated using a magnetic bead particle processor. The whole procedure starting from sample collection can be carried out in few hours, making this assay suitable for high-throughput analysis of mRNAs. One 96-well plate and a pool of 30 probes yields 2880 expression levels in one four-hour -run.
The instrument requirements include a magnetic bead processor and a capillary electrophoresis (CE) device. Different types of bead processors and CE devices are widespread in laboratories involved in molecular biology.

The steps of the TRAC method. After sample lysis (1) the target mRNAs are hybridized with a pool of detection probes and biotinylated  capture probes (2). The targets are immobilized to magnetic beads (3). The magnetic beads are washed and probes are eluted, after which capillary electrophoresis is used to identify and quantify the probes. (4) Data analysis is performed with PlexPress’ proprietary software.

TRAC is a very straightforward method for high-content gene expression analysis, offering several benefits to the user.

• Simple and flexible protocol

TRAC avoids the RNA extraction, cDNA conversion, and amplification steps required in most of the competing methods. This significantly reduces the cost and effort of setting up and running the assay as well as reducing RNA degradation and error rates. The simplicity of the TRAC method also translates to high flexibility in terms of modifying assays and designing new gene panels.

• Rapid assay with high throughput

A TRAC assay requires only 4 hours of process time and can be fully automated for high throughput applications.

• Highly accurate

Due to the simple and robust nature of the TRAC assay, it can achieve CVs of 5-10%, significantly below competing methods.

• Compatible with existing equipment

TRAC is fully compatible with existing 3rd party laboratory equipment, which constitutes a major competitive advantage over competitors that require the purchase of proprietary analysis devices.