Devices and methods for analyzing biomolecules and probes bound thereto
Devices and methods for detecting the length of analytes and/or sequencing analytes are provided in which two or more electrical signals are obtained as an analyte traverses a nanopore or fluidic channel. Detection of the relative position of probes hybridized to a biomolecule and/or the length of the analyte (e.g., a biomolecule) rely on detection events to determine a distance associated with the biomolecule. Multiple signals may be obtained (e.g., as functions of time) corresponding to a plurality of detector volumes at known locations along a fluidic channel through which the biomolecule passes, and the distances may be determined from the multiple signals.
1. An apparatus for analyzing a target biomolecule, the apparatus comprising:
a) first and second fluid chambers in fluid communication with one another, wherein the first and second fluid chambers are separated by a structure defining a member selected from the group consisting of a nanochannel and a microchannel;
b) a plurality of electrodes each laterally offset from one another along at least a portion of a length of the nanochannel or microchannel, to thereby define a plurality of detector volumes therein, the electrodes being in communication with an electrical signal detector and data collection device programmed to respectively detect and record changes in an electrical property corresponding to at least one of the detector volumes as the target biomolecule translocates through the detector volumes, wherein (i) each detector volume is defined by a pair of the electrodes laterally offset from each other along the nanochannel or microchannel, (ii) each pair of laterally offset electrodes comprises a first electrode disposed upstream from a second electrode along a length of the nanochannel or microchannel, and (iii) the plurality of electrodes comprises at least three electrodes defining at least two detector volumes therebetween; and
c) a driving force generator for translocating the target biomolecule from the first fluid chamber to the second fluid chamber through the plurality of detector volumes.
2. The apparatus of claim 1 , wherein the plurality of electrodes comprises a first plurality of n electrodes each laterally offset by a first predetermined distance along the nanochannel or microchannel, to thereby define n−1 detector volumes.
3. The apparatus of claim 2 , having a second plurality of m electrodes each laterally offset by a predetermined distance along the nanochannel or microchannel, to thereby define m−1 detector volumes.
4. The apparatus of claim 3 , wherein the second plurality of electrodes is laterally offset from the first plurality of electrodes by a distance greater than either the first or second predetermined distance.
5. The apparatus of claim 1 , wherein a spacing between each detector volume is predetermined and unequal.
6. The apparatus of claim 5 , wherein the spacings between the plurality of detector volumes define a Golomb ruler.
7. The apparatus of claim 1 , wherein spacings between the detector electrodes of at least two detector volumes are unequal.