Immuno-magnetic cell separation utilizes magnetic beads, paramagnetic particles and magnetic fields to separate target cells from a mixture.  The beads contain an affinity group coating which is specific to the antigens found on the target cells’ surface.  In positive isolation, the targeted cells are labeled by mixing the specimen containing the target cells with these magnetic beads.  This mixture is incubated so that the target cells bind to the coated magnetic beads. A magnetic field is applied to the mixture, typically by placing the suspension between 2 stationary magnets. The target cells, which are tagged by the magnetic particles are attracted to either the container’s surface, or to a metallic column placed in the suspension, depending on the method.  Unmarked cells are flushed from the system and the desired cells are collected following release of the magnetic field.  In depletion or negative isolation, the undesired cells are tagged with the magnetic beads, allowing the desired cells to be collected when the magnetic field is applied.  

 

 

Current technologies do not provide the level of purification required for effective research and development, or for effective clinical use. These technologies deal with small volumes, require hands-on monitoring throughout the separation process and do not effectively separate rare cell populations. Larger, state-of-the-art technologies, damage the cells, resulting in impure specimens.

 

The current "gold-standard" in magnetic cell separation separates cells over a metallic column – the marked cells are retained on the column while the unlabeled cells pass through the system. The marked cells are later collected by plunging them out of the system. The various processes involved in cell separation by this method damage the cells resulting in a high percentage of non-viable cells. The cells themselves are abraded, a state that leads to cell clusters and lowers the purity level of the specimen. After separation, the cells are subjected to a period of aridity, another factor that negatively affects the cells' viability. 

 

 

BioCep’s patented CEP (Cell Enrichment Process) is a novel technology for immuno-magnetic cell separation.  The CEP is a flow through, contact free technology allowing purer separations and undamaged cells. The CEP isolates cells from clinical sources including bone marrow, peripheral blood, cord blood, and cerebrospinal fluids at high yield, purity and viability. The CEP’s capabilities allow rare cell population separations, of even 1 cell in 10⁹ cells.

 

The cell suspension flows through the CEP’s silicone tubing and is propelled through four separation areas by use of gentle peristaltic pumps. The system incorporates electromagnets which allow users to control and define the magnetic field intensity of the separation, creating infinite protocol possibilities.  A specialized physiological fluid is present throughout the separation procedure ensuring that the cells do not suffer from aridity. The marked cells are held in stasis in the harvesting areas and collected following magnetic field release. No abrasive materials are used in this method. The entire process is controlled by a user-friendly touch screen program.

 

 

The CEP can separate any type of cell that can be magnetically marked. Specifically the CEP is particularly suitable for cell isolation for the purpose of:

 

 

 

 

The following is a summary of the main advantages of the CEP:

 

BioCep plans to develop a number of novel clinical applications on its platform, including:

 

 

 

 

Prenatal diagnosis is performed by potentially harmful, invasive procedures. The 2 most popular methods for prenatal diagnosis are CVS (Chorionic Villus Sampling), which is performed in the first trimester and amniocentesis, typically performed in the second trimester.

 

CVS is considered more dangerous than amniocentesis, with a chance of causing births defects in the fetus. Amniocentesis is less dangerous, but both these procedures have a significant miscarriage rate due to the invasive nature of the procedure. Amniocentesis is carried out at a late stage of pregnancy, so that if an abortion is warranted, the mother must endure traumatic and painful childbirth.

 

 

There is no effective method for non-invasive prenatal diagnosis available today. There are non-invasive screening tests, for the possible detection of Down’s syndrome. The most effective screen is the integrated screen which combines first trimester and second trimester blood tests and ultrasounds. This test provides an indication of whether or not the fetus has Down’s syndrome with 95% accuracy.

 

The presence of fetal cells and fetal material in the maternal bloodstream has been known for decades. Despite this fact, there is currently no effective method of isolating these cells from the maternal bloodstream. A number of companies are attempting to utilize DNA fragments found in the maternal bloodstream for parental diagnosis. Their technologies are based on micro-fluidics and PCR amplification of the fragments to reach the required amount of genetic material for analysis. As these are not complete cells, but rather only fragments of the DNA, they cannot ensure an effective genetic screen of the fetus.

 

Cells that are considered highly effective for non invasive prenatal diagnosis are FNRBCs (fetal nucleated red blood cells) as these are complete fetal cells that circulate in the maternal blood stream at very low concentrations. To date, researchers have been unsuccessful in their attempts to effectively separate sufficient FNRBCs for genetic analysis from the maternal bloodstream.

 

 

FNRBCs (fetal nucleated red blood cells) or fetal erythrocytes are fetal cells that pass from the fetus to the mother’s bloodstream during pregnancy. These cells are whole, intact fetal cells and contain the same DNA makeup as the fetus, as they are complete cells and not fragments, and are therefore highly suitable non invasive prenatal diagnosis. Additionally, these cells have a short life span and it is therefore unlikely for them to persist from one pregnancy to another.

 

 

 

BioCep’s Cell Enrichment Process has the ability to isolate rare cell populations, at high purities without damaging the cell membrane or viability. As such BioCep will enable the isolation of FNRBCs from the maternal bloodstream for the purpose of genetic diagnosis of the fetus. As FNRBCs are most abundant in the beginning weeks of pregnancy, this diagnosis should preferably be carried out in the first trimester. This is preferable, as at this stage a simple abortion is still possible, if deemed necessary. As all that is necessary is a simple blood sample, similar to other blood tests required during pregnancy, the BioCep alternative is considered a non-invasive method of genetic diagnosis of the fetus. Cells obtained via CEP separation can be analyzed for the main trisomies commonly found in fetuses and the test will provide diagnosis of these trisomies with near 100% certainty.

 

BioCep does not alter the genetic analysis procedure as it is done to date on fetal material obtained from amniocentesis or CVS. Genetic labs will receive blood samples taken from mothers in the first trimester. These labs will isolate the FNRBCs from these samples over the CEP. With the CEP isolated cells, the labs can utilize their usual methods for genetic analysis.

 

 

BioCep will perform an accurate analysis of number, viability and purity by using a FACS with Fetal Hemoglobin (HbF) and Propidiumiodide Solution and May-Grunwald/Giemsa staining.

 

 

15 ml

 

 

The preferred blood collection method for CEP test is venipuncture using vacuum collection tubes. The method of collection is similar for whole blood, except for the anticoagulant used. Blood should be obtained from a freely flowing venipuncture performed according to current nursing or laboratory venipuncture procedures. Tubes should be inverted gently in order to mix the anticoagulant. Tubes should be sent to the cytogenetic labs on cold pack or wet ice.