Reagent cuts proteomics workload
proteomics and biomarker discovery experiments by allowing up to
four peptides to be analysed in single sample, writes Wai Lang
Chu.
The iTraq reagents are suitable for various aspects of quantitative biology including membrane protein studies, discovery and validation analysis for biomarker elucidation, and absolute quantitation of target proteins of interest.
In addition the reagents will allow researchers to simultaneously measure expression profiles of multiple samples, such as normal versus diseased versus drug-treated states in a single experiment.
Michael Hunkapiller, president of Applied Biosystems, said: "To elucidate even relatively simple cellular pathways, researchers need to draw comparisons between normal versus disease states to clearly understand up or down regulation of proteins."
The ability to analyse up to four different samples simultaneously gives experimental-design flexibility.
"With ... the iTraq reagents investigators, for the first time, can simultaneously identify and determine relative and absolute quantity of proteins across multiple samples."
The introduction of these reagents expands Applied Biosystems' family of chemistries for protein identification and quantitation. The company already markets the ICAT range, which was introduced in 2001 and focuses specifically on quantifying proteins that contain the amino acid cysteine.
The reagents are based on an isobaric peptide tagging system that enables labelling of all primary amines, regardless of peptide class. This leads to broader protein and proteome coverage with the ability to detect post-translational modifications, and to compare four samples in the same experiment.
Robert Olafson, director of the Genome BC Proteome Centre, said: "One of the biggest advantages is the ability to analyse multiple peptides simultaneously to gain confidence in identification and expression values."
"By running multiple samples in a single experiment, we can expand the range of our possible experiments while reducing our costs."
The reagents have been extensively tested at key worldwide labs, including the University of Victoria, British Columbia, Canada, and OSI Pharmaceuticals Inc.
Applied Biosystems has also launched a software package, called Pro Quant, to analyse data resulting from expression analysis with iTraq reagents. The software features automatic data processing, including quantitation, protein identification and reporting in real-time or batch mode.
The iTraq reagents and Pro Quant Software will become available on the Applied Biosystems 4700 Proteomics Analyzer during summer 2004.
New tech for tissue typing
Meanwhile, Applied Biosystems said it plans to launch a tissue imaging technology for its QStar System, which allows researchers to study the metabolism and distribution of drugs throughout tissue via new imaging software and an extremely fast high-repetition laser.
The new system generates precise 2-dimensional and 3-dimensional images of low molecular weight drug compounds in tissue samples and displays the spatial distribution of drugs, which can help determine whether a drug is reaching its intended target site or accumulating in the tissue.
This research method could eventually lead to the recommendation of more appropriately prescribed treatment regimens, the ability to determine a drug's efficacy, as well as lead to the avoidance of unnecessary side effects from overly aggressive treatment regimens, accoridng to the company.
Commercial shipment is intended to begin in the autumn.
