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Product Information

MassARRAY® QGE precisely measures gene expression levels from a wide variety of samples using real competitive PCR and MALDI-TOF MS. It is the ideal solution for post-array validation and multiplexed application.

  • Ideal for investigating a few or several hundred regions over multiple samples
  • >10-1,000 times greater sensitivity over real-time PCR
  • Multiplex up to 24 targets per reaction
  • High precision over a large dynamic range
  • Most comprehensive data normalization solution for accurate quantification

Applications for QGE

  • Post-array validation
  • Splice variant analysis
  • Biomarker characterization
  • Disease association studies
  • Loss of heterozygosity
  • Viral load quantification
  • Infection resistance and drug response

QGE Chemistry overview

QGE Performance (Read More)

Through dilution experiments conducted in an independent study, it has been demonstrated that there is not a statistically significant difference between the results from QGE and RT-PCR except sensitivity. Ratios for 12 different assays with up to 10,000 fold differences in expression levels were specifically compared.

Results

Comparing ratios for 12 different assays with up to 10,000 fold differences in expression levels it has been reported that there is not statistically significant difference between the results from QGE and RT-PCR; except sensitivity.

  • 100% of MassARRAY® QGE assays worked first-pass with standardized PCR conditions
  • 42% of assays failed first pass in RT-PCR
  • ~50-100 times less total RNA was used in QGE
  • Greater sensitivity was obtained with QGE
  • Uniform standard conditions can be used with QGE

Elvidge et al. Anal. Biochem., Vol. 339, 2005

Results
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Feature MassARRAY® QGE Advantage
Multiplexing
  • Multiplex up to 24 targets per reaction
  • Examine 20-200 genes for larger sample studies
  • Compare absolute levels of gene expression within the same biological sample
  • Rapidly assess optimal reference gene sets for data normalization
Sensity and LOQ
  • Detect as little as a single molecule
  • Start with as little as 5 pg material
  • Differentiate 10% change in expression levels
  • Get high precision (~3% RSD) over a large dynamic range
Assay Designer
  • Run universal reaction conditions
  • Minimize PCR optimization
  • Rapidely design optimal plex sets

Data Normalization (Read More)

The Value and Ease of Data Normalization

The primary goal of normalization is to compare quantitative expression data between different samples, experiments, and periods of study. It is important to account for variability in

  • RNA quality
  • Cellular input/RNA quantity
  • Reverse transcription efficiency
  • Pipetting inaccuracies
  • Endogenous/biological variance

Challenges of Current Methods

  • Use of total RNA fails to account for reverse transcription efficiency
  • Ribosomal RNA may differ during diverse biological states and is present in much greater amounts than the transcript of interest
  • Use of a single endogenous control gene may be subject to transcriptional changes as a result of the biological process

Solution

Data Normalization with MassARRAY® QGE & geNorm

  • Multiplex a panel of reference genes in a single reaction to determine the best candidates for data normalization
  •  Easy-to-use Visual Basic Application
  •  Over 650 citations have referenced the importance of data normalization using the geNorm technique

 

Note: The MassARRAY Analyzer 4 system, OncoCarta, iPLEX Gold, iSEQ, QGE, EpiTYPER, TYPER software, iPLEX ADME PGx panel , iPLEX ID Panel, Assay Explorer and MelaCarta are for Research Use Only. Not for Use in Diagnostic Procedures.