System for identifying and targeting individual cells within a heterogeneous population for selective extraction of cellular content

Abstract

The present disclosure provides a system and method for identifying and targeting individual cells within a cell population for selective extraction of cellular content and a digital microfluidic device having at least one hydrophilic site for receiving cells, an imaging system including a stage for receiving the digital microfluidic device and an imaging module for identifying at least one targeted cell among the cells at the at least one hydrophilic site. The system includes a pulsed laser source for laser lysing the targeted cell thereby releasing the cell content to produce a lysate. A control system controls the pulsed laser source, the imaging system and the digital microfluidic device and is programmed for coordinating steps of i) movement of droplets on the digital microfluidic device, ii) selection of the at least one targeted cell to be lysed located at the at least one hydrophilic site, iii) illumination of the at least one selected targeted cell by the pulsed laser source to lyse the at least one selected targeted cell to produce lysate, and iv) collection of the lysate.

1 - 14 . (canceled) 
     
     
         15 . A method for detection and/or isolation of fetal cells and/or fetal analytes, the method comprising:
 loading a sample containing cells on at least one site of a digital microfluidic device thereby forming a virtual microwell at each of the at least one site;   Immobilizing the cells on the at least one site;   selecting at least one immobilized cell;   lysing the at least one selected cell using a pulsed laser source to produce lysate within its corresponding virtual microwell;   displacing a droplet of liquid to the corresponding virtual microwell for collecting the lysate; and   moving the droplet containing the lysate from the corresponding virtual microwell to a designated site, and optionally detecting and/or isolating fetal analytes in the lysate.   
     
     
         16 . The method according to  claim 15  wherein the at least one site is hydrophilic, partially hydrophilic or become hydrophilic after protein fouling/adsorption from the sample. 
     
     
         17 . The method according to  claim 15  further including a step of generating a map of locations of the immobilized cells, and wherein the step of selecting the at least one immobilized cell includes selecting the at least one cell from the map. 
     
     
         18 . The method of  claim 15  further comprising a step of labelling the immobilized cells. 
     
     
         19 . The method of  claim 18  wherein the step of labelling the immobilized cells further comprises fixing the cells. 
     
     
         20 . The method of  claim 15  further comprising steps of:
 moving the digital microfluidic device along horizontal axes and a vertical axis for positioning the digital microfluidic device for lysing another at least one selected cell from immobilized cells; 
 lysing the other at least one selected cell using the pulsed laser source to produce another lysate within its corresponding virtual microwell; 
 displacing another droplet of liquid to the corresponding virtual microwell for collecting the other lysate; and 
 moving the other droplet containing the other lysate from the corresponding virtual microwell to a designated site. 
 
     
     
         21 . The method of  claim 15  further comprising a step of introducing the sample containing the cells at an initial site and displacing the sample to the at least one site. 
     
     
         22 . The method of  claim 15 , wherein said at least one site is a plurality of sites, and including steps of
 moving of droplets to said plurality of sites,   selecting of a cells to be lysed at each of said plurality of sites,   selecting a first site to illuminate the selected cell at that site,   moving of the stage to move the digital microfluidic device sequentially to bring each of the sites into a field of view of the pulsed laser source to lyse the selected cell to produce lysate at each site, and   collecting the lysate at each site.   
     
     
         23 . The method according to  claim 22  including calculating a shortest distance travelled by the stage to bring each of the plurality of sites into the field of view of the pulsed laser source sequentially. 
     
     
         24 . The method according to  claim 22  wherein the at least one selected targeted cell is a plurality of selected targeted cells, including
 identifying a sequence of selected targeted cells to be lysed to minimize a time to perform the lysing on all selected targeted cells, and 
 
       wherein the plurality of selected targeted cells is within one field of view, or a plurality of field of views, or within a plurality of sites. 
     
     
         25 . The method of  claim 15  wherein the pulsed laser source is a nanosecond-pulsed laser. 
     
     
         26 . The method of  claim 15  wherein the pulsed laser source is a nanosecond-pulsed laser delivering pulses of at least 1 μJ. 
     
     
         27 . The method according to  claim 25 , wherein the nanosecond-pulsed laser is a Nd-based laser. 
     
     
         28 . The method according to  claim 25 , wherein the nanosecond-pulsed laser produces a pulsed-laser beam within the visible spectrum. 
     
     
         29 . The method of  claim 15 , wherein the pulsed laser source is a Q-switched laser. 
     
     
         30 . The method of  claim 15 , further comprising the step of performing on chip analysis of the lysate at the designated site. 
     
     
         31 . The method of  claim 30 , further comprising the step of collecting the droplet containing the lysate from the designated site for off-chip analysis. 
     
     
         32 . (canceled) 
     
     
         33 . The method according to  claim 15  for prenatal genetic testing or screening, or detection or diagnosis of a prenatal condition. 
     
     
         34 . (canceled)