Project Acronym:

Project Reference:

Duration: 36 months

Contract Type:
Small or medium-scale
focused research project

Project Funding:
5 million euro

Research area:
HEALTH.2013-0-1: Boosting the translation of health research projects results into innovative applications for health


In situ PLA Technology

Two primary antibodies raised in different species recognize the target antigen or antigens of interest. Species-specific secondary antibodies, called PLA probes, each with a unique short DNA strand attached to it, bind to the primary antibodies. When the PLA probes are in close proximity (<40 nm), the DNA strands can interact through a subsequent addition of two other circle-forming DNA oligonucleotides. After joining of the two added oligonucleotides by enzymatic ligation, they are amplified via rolling circle amplification using a polymerase. After the amplification reaction, several-hundredfold replication of the DNA circle has occurred, and labeled complementary oligonucleotide probes highlight the product. The resulting high concentration of fluorescence in each single-molecule amplification product is easily visible as a distinct bright dot when viewed with a fluorescence microscope.

Duolink video: the principle of in situ PLA


How CytoTrack works

The basic idea of CytoTrack is very much related to the conventional CD/DVD technology. The sample is spread on a CytoTrack glass disc that has a large area (25 times larger than the efficient area of a standard microscope slide).

The disc is placed within the CytoTrack scanner that rotates the disc with a high velocity. The sample is scanned with a laser beam in a helix pattern (fluorescent scanning). All data from the scanning is processed by the CytoTrack data management system that selects the targets and captures the exact position of each single target cell on the disc.

After the primary scan, each target is revisited for image analysis and further detection.

The procedure (sample preparation)

1) A blood sample is drawn from the patient

2) The red blood cells are disposed by lysis

3) The sample is stained, immunohistochemical process (antibody)

4) The sample is spread evenly on a CytoTrack disc

5) The sample on the disc is immobilized

The procedure (scanning)

6) The disc is scanned within the CytoTrack instrument

7) All data are processed and results are displayed

8) Each target cell is revisited for verification by imaging

9) Target cells are further characterized (pheno/geno) on the disc

The preparation process steps are performed as a standard laboratory working process. The scanning procedure is commonly performed in just 10-15 minutes per sample.

Cytotrack video presentation


The CELLSEARCH® CTC Test is the first and only clinically validated, FDA-cleared system for identification, isolation, and enumeration of circulating tumor cells

Clinical studies have demonstrated that the number of CTCs associates with disease prognosis and provides an important marker for assessing patients’ status throughout the continuum of treatment. However, even in patients with advanced cancer, CTCs are rare in the blood, estimated at 1 per billion of normal blood cells. Thus, developing a reliable method for capturing and enumerating CTCs has presented a major challenge.

The CELLSEARCH® System is the result of 15 years of research and technical innovation that led to the first standardized, FDA-cleared semi-automated system that detects and enumerates CTCs of epithelial origin (CD45-, EpCAM+, and cytokeratins 8+, 18+, and/or 19+) from a 7.5-mL blood sample with a high level of sensitivity and specificity.

The CELLSEARCH® System uses unique immunomagnetic and fluorescence imaging technology to provide rapid, precise, and reproducible analysis of CTCs with a simple 3-step process: sample collection, sample preparation, and sample analysis.