Isotachophoresis for purification of nucleic acids
The present disclosure relates to fluidic systems and devices for processing, extracting, or purifying one or more analytes. These systems and devices can be used for processing samples and extracting nucleic acids, for example by isotachophoresis. In particular, the systems and related methods can allow for extraction of nucleic acids, including non-crosslinked nucleic acids, from samples such as tissue or cells. The systems and devices can also be used for multiplex parallel sample processing.
1. A method for simultaneously purifying nucleic acids from at least two different samples comprising:
(a) loading into a first channel of a microfluidic chip (i) a first sample comprising first nucleic acids and a first contaminant, (ii) a first trailing electrolyte buffer comprising first trailing ions, wherein a magnitude of an effective mobility of said first trailing ions is less than a magnitude of an effective mobility of said first nucleic acids, and (iii) a first leading electrolyte buffer comprising first leading ions, wherein a magnitude of an effective mobility of said first leading ions is greater than said magnitude of said effective mobility of said first nucleic acids;
(b) loading into a second channel of said microfluidic chip (i) a second sample comprising second nucleic acids and a second contaminant, (ii) a second trailing electrolyte buffer comprising second trailing ions, wherein a magnitude of said second trailing ions is less than a magnitude of an effective mobility of said second nucleic acids, and (iii) a second leading electrolyte buffer comprising second leading ions, wherein a magnitude of an effective mobility of said second leading ions is greater than said magnitude of said effective mobility of said second nucleic acids;
(c) independently controlling a first electric circuit connected to said microfluidic chip to conduct isotachophoresis in said first channel with said first trailing ions, said first nucleic acids, and said first leading ions, and independently controlling a second electric circuit to conduct isotachophoresis in said second channel with said second trailing ions, said second nucleic acids, and said second leading ions, thereby simultaneously purifying said first nucleic acids from said first contaminant and said second nucleic acids from said second contaminant; and
(d) after independently controlling said first and second electric circuits, applying said first electric circuit or a third electric circuit to conduct isotachophoresis in a third channel in liquid communication with said first channel, and applying said second electric circuit or a fourth electric circuit in a fourth channel in liquid communication with said second channel, wherein said third and fourth channels comprise first and second elution buffers, respectively.
2. The method of claim 1 , wherein said first trailing electrolyte buffer or said first leading electrolyte buffer further comprises a cell lysis agent or a tissue disruption agent.
3. The method of claim 2 , wherein said lysis agent or said tissue disruption agent comprises one or more agents selected from the group consisting of: a solution with pH greater than about 12, a proteinase, urea, thiourea, and a surfactant.
4. The method of claim 1 , wherein said first sample comprises lysed solid tissue or lysed cells.
5. The method of claim 1 , wherein current leakage between said first channel and second channel is less than 1 uA.
6. The method of claim 1 , further comprising:
(a) loading into a fifth channel of said microfluidic chip (i) a third sample comprising third nucleic acids and a third contaminant, (ii) a third trailing electrolyte buffer comprising third trailing ions, wherein a magnitude of an effective mobility of said third trailing ions is less than a magnitude of an effective mobility of said third nucleic acids, and (iii) a third leading electrolyte buffer comprising third leading ions, wherein a magnitude of an effective mobility of said third leading ions is greater than said magnitude of said effective mobility of said third nucleic acids, and
(b) independently controlling a fifth electric circuit connected to said microfluidic chip to conduct isotachophoresis in said fifth channel with said third trailing ions, said third nucleic acids, and said third leading ions, thereby simultaneously purifying said first nucleic acids from said first contaminant, said second nucleic acids from said second contaminant, and said third nucleic acids from said third contaminant.
7. The method of claim 1 , wherein said first and second electric circuits are generated from different sets of electrodes.
8. The method of claim 7 , wherein said first and second channels are coupled to independent sensors.
9. The method of claim 8 , wherein feedback signals from said independent sensors is used to independently control said first and second electric circuits.
10. The method of claim 9 , wherein said independent sensors detect voltage and said feedback signals are used to control current within said first and second channels.
11. The method of claim 9 , wherein said independent sensors detect current and said feedback is used to control voltage within said first and second channels.
12. The method of claim 1 , wherein each channel has a dedicated set of electrodes and electric circuitry to drive isotachoporesis.
13. The method of claim 1 , wherein said first nucleic acids comprise DNA.
14. The method of claim 1 , wherein said first nucleic acids comprise RNA.
15. The method of claim 1 , wherein said first sample or said second sample comprises fixed cells, fixed tissue, or embedded tissue.
16. The method of claim 1 , further comprising eluting a first output solution comprising said purified first nucleic acid from a first outlet reservoir of said first elution channel and eluting a second output solution comprising said purified second nucleic acids from a second outlet reservoir of said second elution channel.
17. The method claim of claim 1 , wherein step (d) comprises: after independently controlling said first and second electric circuits, applying said first electric circuit to conduct isotachophoresis in said third channel in liquid communication with said first channel, and applying said second electric circuit in said fourth channel in liquid communication with said second channel.
18. The method claim of claim 17 , wherein said first and second channels are coupled to independent sensors and wherein feedback signals from said independent sensors are used to independently control said first and second electric circuits.
19. The method claim of claim 18 , wherein said independent sensors detect voltage and said feedback signals are used to control current within said first and second channels.
20. The method claim of claim 18 , wherein said independent sensors detect current and said feedback signals are used to control voltage within said first and second channels.
21. The method claim of claim 17 , wherein said nucleic acids comprise DNA.
22. The method claim of claim 17 , wherein said nucleic acids comprise RNA.
23. The method claim of claim 1 , wherein step (d) comprises: after independently controlling said first and second electric circuits, applying said third electric circuit to conduct isotachophoresis in said third channel in liquid communication with said first channel, and applying said fourth electric circuit in said fourth channel in liquid communication with said second channel.
24. The method claim of claim 23 , wherein said first and second channels are coupled to independent sensors and wherein feedback signals from said independent sensors are used to independently control said first and second electric circuits.
25. The method claim of claim 24 , wherein said independent sensors detect voltage and said feedback signals are used to control current within said first and second channels.
26. The method claim of claim 25 , wherein said independent sensors detect current and said feedback signals are used to control voltage within said first and second channels.
27. The method claim of claim 23 , wherein said nucleic acids comprise DNA.
28. The method claim of claim 23 , wherein said nucleic acids comprise RNA.