Circulating Tumor Cells

Single Cell Analysis

Point of Care

Application Development






Isolation of Circulating Tumor Cells (CTC)


Filtration system


For the filtration of CTC from whole blood, VyCAP designed a disposable filtration unit that holds a slide with a silicon microsieve. The number of pores, diameter and inter pore spacing was optimized to obtain the highest recovery of CTC. Because of the very thin membrane the flow resistance of the microsieves is very low compared to comparable filtering systems. This allows the use of a low pressure resulting in less force on the captured cells and less cell damage.  


The filtration system consists of three parts:

1.     Pump unit

2.     Disposable filtration unit

3.     Slide with a microsieve


The disposable filtration unit is pushed onto the pump unit hereby connecting the waste compartment to the vacuum pump. The sample is added to the sample compartment and flows through the pores of the microsieve membrane towards the waste compartment while the objects of interest stay behind on the membrane. For EDTA whole blood, a pressure of 25 mbar (0.36 PSI) results in a flow rate of approximately 1 ml / min. After the whole sample passed through the microsieve, the slide with microsieve is easily pulled out from the disposable filtration unit.


To stain the collected cells on the microsieve, the slide is transferred to our staining holder





Staining holder


The staining holder is an indispensable item for staining, fixation and washing of the collected cells, without losing the cells. After the slide is removed from the disposable filtration unit, it is placed into the staining holder.

Next, the staining reagents are added onto the microsieve and the cells (Step 1). The staining reagents will stay on the microsieve and in contact with the cells during incubation (Step 2). After incubation the excess reagents are easily removed by pushing the microsieve down onto an absorbing pad that is positioned below the microsieve (Step 3). This process can be repeated multiple times with different reagents. The cells will remain on the sieve and will not be washed away during these multiple staining steps.

Analysis cycle


Step 1 :    Transfer the sample fluid, in this case whole blood, to the sample compartment


Step 2 :    Switch on the pump unit

Wait until the whole sample passed through the microsieve


Step 3 :    Remove the slide with microsieve that contains the collected cells


Step 4 :    Transfer the slide to the staining holder and add staining reagent onto the sieve

                 After incubation push the slide down onto the absorber to remove excess reagents

                 (step 4 can be repeated multiple times with different reagents without losing the cells)


Step 5 :    Acquire fluorescence images


The steps as listed above are captured in a movie that can be viewed here.



Image presents part of the microsieve after EDTA whole blood filtration, followed by staining of the cells on the sieve.