BD BCR-ABL Protein Kit
In May, BD Biosciences released a new BCR-ABL Protein Kit for determining the presence of BCR-ABL fusion proteins. The new kit detects the presence of specific fusion proteins in cell lysates and is based on the BD™ Cytometric Bead Array (CBA) system.
About fusion proteins
Fusion proteins are a consequence of chromosomal rearrangements in a cell. Some chromosomal rearrangements lead to changes in the positions of genes, which ultimately cause the cells to generate altered proteins. Fusion proteins are absent from normal, healthy cells. Fusion proteins have antigen determinants derived from each of the original proteins that would not normally be present on the same molecular structure. By introducing two antibodies into a sample, each specific to an antigen on a different portion, it is possible to detect the presence of a fusion protein.
Principle of the assay
Flow cytometry allows for the discrimination of particles on the basis of attributes such as size and fluorescence. BD CBA systems provide a way of coupling a soluble analyte or set of analytes with beads of known size and fluorescence, making it possible to detect analytes through flow cytometry.1 The BD™ BCR-ABL Protein Kit uses this technology to detect BCR-ABL fusion proteins2 in human blood research samples.
About the assay kit
The BD BCR-ABL Protein Kit, a bead-based immunoassay, takes advantage of flow cytometry's excellent fluorescence detection capabilities. Key components in the kit are the capture beads, which are stained particles coated with an antibody, and the detector antibodies, which are conjugated to a fluorescent dye.
The capture beads included in this kit have been coated with an antibody specific to one part of the BCR-ABL fusion protein. The detector reagent is a phycoerythrin (PE)-conjugated antibody specific to a different part of the protein. The capture beads and detector reagent are incubated with a prepared sample. If the sample contains BCR-ABL proteins, sandwich complexes are formed, as shown in Figure 2.
These sandwich complexes can be studied by using flow cytometry to identify particles with attributes of both the bead and the detector.
Kit contents
- Pretreatment A (powder), store at -20°C.
- Pretreatment B (powder), store at 2°C to 8°C.
- Capture beads, store in the dark at 2°C to 8°C.
- Detector reagent, store in the dark at 2°C to 8°C.
Figure 1. Once cell lysates are prepared using the BD BCR-ABL Protein Kit and samples are run in the flow cytometer, histograms show the presence or absence of BCR-ABL fusion proteins.
Figure 2. Formation of sandwich complexes in the BCR-ABL immunoassay.
References
1. Morgan E, Varro R, Sepulveda H, et al. Cytometric bead array: a multiplexed assay platform with applications in various areas of biology. Clin Immunol. 2004;110:252-266.
2. Ben-Neriah Y, Daley GQ, Mes-Masson AM, Witte ON, Baltimore D. The chronic myelogenous leukemia-specific P210 protein is the product of the bcr/ abl hybrid gene. Science. 1986;233:212-214.