Microfluidic single-cell pairing array for studying cell-cell interactions in isolated compartments
View Patent ↗A microfluidic device having an array for cell trapping is used to analyze cell-cell interaction at single-cell level. The microfluidic trapping array efficiently pairs single cells in isolated compartments in an easy-to-operate manner. A first cell is squeezed through an opening of a first cavity by a strong forward flow. Subsequently, a second cell is pushed into a second cavity by a low reverse flow. The trapped cell pairs are sealed by an oil phase or hydrogel into isolated compartments, thereby eliminating interference from other cell pairs or the surrounding media.
1. A method of trapping cells, said method comprising:
a. providing a microfluidic device ( 100 ) comprising;
i. a serpentine channel ( 110 ) having a plurality of parallel channel portions ( 112 ); and
ii) a plurality of microfluidic trapping arrays ( 105 ), wherein each array of the plurality of microfluidic trapping arrays ( 105 ) is disposed between two adjacent parallel channel portions ( 112 ) of the serpentine channel ( 110 ) such that one channel portion of the two adjacent parallel channel portions is disposed on a first side ( 107 ) of each array and the other channel portion of the two adjacent parallel channel portions is disposed on a second side ( 109 ) of each array that is opposite of the first side ( 107 ), wherein each array of the plurality of microfluidic trapping arrays ( 105 ) comprises one or more trapping structures ( 120 ), each trapping structure ( 120 ) comprising:
1. a first cavity ( 130 ) having an opening ( 132 ) facing the channel portion disposed on the first side ( 107 ) and a first relief channel ( 134 ) fluidly connecting the first cavity ( 130 ) to the channel portion disposed on the second side ( 109 );
2. a second cavity ( 140 ) adjacent to the first cavity ( 130 ), wherein the second cavity ( 140 ) has an opening ( 142 ) facing the channel portion on the second side ( 109 ) and a second relief channel ( 144 ) fluidly connecting the second cavity ( 140 ) to the channel portion on the first side ( 104 ); and
3. a connecting channel ( 150 ) disposed between and fluidly connecting the first cavity ( 130 ) and the second cavity ( 120 );
b. flowing a first fluid having a plurality of first cells ( 202 ) in a forward flow direction through the serpentine channel ( 110 ) such that a first cell ( 202 ) enters the first cavity ( 130 ) of a trapping structure by squeezing through the opening ( 132 ) of said first cavity, wherein said first cavity ( 130 ) is occupied by one first cell ( 202 );
c. flowing a second fluid having a plurality of second cells ( 204 ) in a reverse flow direction through the serpentine channel ( 110 ) such that a second cell ( 204 ) enters the second cavity ( 140 ) of the trapping structure by squeezing through the opening ( 142 ) of said second cavity, wherein said second cavity ( 140 ) is occupied by one second cell ( 204 ), thereby forming a cell pair ( 200 ) comprising the first cell ( 202 ) and the second cell ( 204 ) trapped in the trapping structure.
2. The method of claim 1 further comprising flowing a sealing fluid ( 205 ) in either flow direction so as to seal the cell pair ( 200 ) such that the cell pair ( 200 ) is confined within and isolated in the trapping structure, thereby blocking interference from other cell pairs ( 200 ) or surrounding media.
3. The method of claim 1 , wherein the first fluid flows at a rate such that the first cell is deformed and squeezed through the opening.
4. The method of claim 1 , wherein a flow rate of the second fluid in the reverse flow direction is lower than a flow rate of the first fluid in the forward flow direction.
5. The method of claim 1 , wherein the method traps cells such that at least 50% of the trapping structures are occupied by cell pairs.
6. The method of claim 1 , wherein the method traps cells for analysis of cell-cell interactions.