qBead™ Multiplex Gene Expression Assay

qBead Overview

The qBead gene expression assay measures the expression of mRNA transcripts by combining High Throughput Genomics (HTG) qNPA™ Chemistry and Luminex xMAP^® Technology. qNPA (quantitative Nuclease Protection Assay) is a proven method well suited for fixed tissues, challenging samples and a broad range of sample types including FFPE, cell cultures, frozen tissues, saliva, blood, drosophila, plant, fungi, yeast, bacteria and virus. Samples can be analyzed without the need for RNA extraction, amplification, or purification. The xMAP Technology allows detection of up to 50 analytes/sample on the MAGPIX^® instrument, 80 analytes/sample on a Luminex^® 100/200™ and greater than 80 analytes/sample on a FLEXMAP 3D^®. The qBead assay embodies a simple workflow with highly sensitive and specific results on a flexible and high-throughput platform.

Nuclease Protection Assay

The quantitative Nuclease Protection Assay (qNPA) starts with the lysis of the cells, tissue or other sample type. Nuclease protection DNA probes are added to cell lysates and bind to target RNA transcripts. Unhybridized (unprotected) RNA or DNA probes are digested by S1 nuclease. Protected RNAs are removed to expose nuclease protection probes. These protected DNA probes are ready for hybridization with the qBead microspheres.

Microsphere Hybridization and Quantification

Each microsphere of the qBead assay is programmed to capture one or more nuclease protection probes from a single, targeted mRNA transcript. The protected DNA probes from the nuclease protection assay are added and hybridized with the programming linkers on the pre-programmed microspheres. In the next step of the hybridization, detection linkers are added which hybridize to the nuclease protection probes. In the last step, biotinylated detection probes are added to hybridize to the detection linkers. After an SA-PE incubation, the samples are ready to be quantified with a Luminex 100/200 or FLEXMAP 3D. 

qBead Overview

qBead Assay Performance

Sensitivity and Linearity

In an experiment performed on a 39-gene housekeeping panel, most low expression genes are detectable above background level at 1,600 cells. Linearity up to at least 100,000 cells is observed. Results on both Luminex^® 100/200™ and FLEXMAP 3D^® are comparable with a greater degree of linearity observed on FLEXMAP 3D.

qBead Sensitivity and Linearity
 
Sensitivity and linearity of qBead assay in a cell titration study with a 39-gene housekeeping panel. The assay was performed in triplicates and analyzed on both Luminex 200 and FLEXMAP 3D instruments. Signals (MFIs) are log2-transformed. Average %CV: 11%, 13%, Luminex 200 and FLEXMAP 3D, respectively.

Reproducibility

qBead is a robust assay with high degree of reproducibility. Both intra- and inter-run %CVs of the 39-gene housekeeping panel are <15%. Inter-instrument signal correlation is > 0.99.

qBead Reproducibility

Excellent correlation of signals within a run (Luminex 100/200), between runs (FLEXMAP 3D) and between Luminex 200 and FLEXMAP 3D (Inter-instrument graph: x-axis = FLEXMAP 3D; y-axis = Luminex 200).

qBead Workflow

Downloads

Document	Language	Type	Download
HTG Information
HTG Technology
HTG Literature
qNPA
MSDS
Manual
qBead Multiplex Gene Expression Assay User Manual	English	pdf
Data Sheets and Brochures
qBead Gene Expression Solution	English	pdf
Performance of the qBead Gene Expression Assay as Compared to Affymetrix, Illumina, and TaqMan® Methods	English	pdf
qBead Multiplex Gene Expression Assay Performance	English	pdf
qBead 41-Plex Housekeeping Panel	English	pdf

qBead Training Courses

Please contact your regional Luminex Business Manager or Luminex Technical Support for more information. Additional training for Luminex products is available at xMAP University.

Support Information

Luminex offers comprehensive technical support enabling companies and laboratories to perform bioassays quickly, accurately, and cost effectively while optimizing the customer experience with Luminex systems.

Ordering Information