Liquid biopsies platform
PREPARATION OF BLOOD DERIVED PRODUCTS
The Biobank Côte d’Azur stores, not only whole blood from patients, but also prepares and stores its derivatives, such as plasma, serum, pellets obtained after plasma preparation, platelets and PBMCs. Each preparation is made according to procedures validated within the laboratory itself, but any specific requests for preparation can be taken into account for our customers.
Depending on the source of the sample, the tubes are different: for all samples that can be processed within 4 hours in our laboratory, conventional EDTA tubes are used. For the other samples, Streck tubes are recommended (https://www.streck.com/collection/cell-free-dna-bct/)
PREPARATION OF URINE DERIVED PRODUCTS
The existence of DNA in excreted urine is now well-established and represents a potentially useful source of genetic material. In this context, the Biobank Côte d’Azur collects urine samples from non-small cell lung cancer (NSCLC) and Chronic Obstructive Pulmonary Disease (COPD) patients in particular. These urine samples are immediately stored at -80°C without any intermediary procedures as soon as they arrive at the biobank. They are then used in research projects such as the UrinAIR project, which aims to compare the detection of EGFR mutations in plasma and urine of NSCLC patients at baseline and during their monitoring, as well as to study air pollutants in urine from COPD patients with high risk of lung cancer.
HIGHLIGHTS OF CIRCULATING TUMOR CELLS
With a simple blood test, it can be possible to detect the early presence of circulating tumor cells in the blood. Two techniques are currently used in the laboratory for research projects: ISET (Rarecells® Diagnostics; http://www.isetbyrarecells.com/fr/) and CellSearch (Veridex; https://www.cellsearchctc.com).
The ISET (Isolation by Size of Epithelial Tumor cells) blood filtration technique is performed directly on the patient's whole blood. 10 mL of whole blood are used to pass through this ISET filter (10 small filters on the same support), which retain only the cells whose size is greater than 8 microns, including circulating tumor cells. The cells are then ready to be stained or immunohistochemically labeled (staining or markings may be required for the same patient test). A pathologist specializing in this technique, belonging to our laboratory, characterizes these cells.
The CellSearch technique is also performed directly on the patient's whole blood (collected in CellSave tubes) to detect Circulating Rare Cells. This tool can be used across several medical fields, including oncology. Currently, Veridex produces three kits: (1) for the detection of Circulating Tumor Cells, (2) for the detection of Circulating Endothelial Cells and (3) for the detection of Circulating Melanoma Cells.
The whole blood, after having been prepared according to a defined protocol, enters the first automaton step, the CellTracks® Autoprep® System, which allows immunomagnetism purification of the labeled cells. In the second step, fluorescent immunostaining of the target cells occurs. This preparation is then processed by a second PLC, the CellTracks Analyzer II®, which counts and characterizes all possible selected rare cells, along with image storage. Dedicated software sorts the data for validation by an authorized engineer from our laboratory.