Method and apparatus for quantitative determination of accumulations of magnetic particles
First Claim
Patent Images
1. Apparatus for making quantitative measurements of agglutinations of magnetic particles comprising complexes of non-magnetized, magnetizable particles and target molecules, said apparatus comprising:
- a substrate configured to receive samples of the agglutinations including unknown quantities of said magnetic particles in defined patterns thereon, the magnetizable particles in the samples being of known size and magnetic characteristics bound to the target molecules;
a magnet for providing a DC magnetic field, the magnetic field producing magnetization in the magnetizable particles when they are in the magnetic field;
at least one magnetic field sensing element in the magnetic field, said sensing element having an output signal conductor and producing an output signal when the samples are in operative relationship with said at least one sensing element; and
, a signal processor for converting said output signals from said at least one sensing element to provide a signal indicative of the quantity of the target molecules in a sample pattern.
3 Assignments
0 Petitions
Accused Products
Abstract
Apparatus for detection and measurement of agglutinations of magnetic particles employing Hall sensors. A low frequency AC signal is employed to excite or bias the Hall sensors which reside in a DC magnetic field. The particles are moved into operative relationship with the Hall sensors in order to generate a signal representing the number of particles on the substrate. The method for such detection and measurement is also part of the invention.
-
Citations
53 Claims
-
1. Apparatus for making quantitative measurements of agglutinations of magnetic particles comprising complexes of non-magnetized, magnetizable particles and target molecules, said apparatus comprising:
-
a substrate configured to receive samples of the agglutinations including unknown quantities of said magnetic particles in defined patterns thereon, the magnetizable particles in the samples being of known size and magnetic characteristics bound to the target molecules;
a magnet for providing a DC magnetic field, the magnetic field producing magnetization in the magnetizable particles when they are in the magnetic field;
at least one magnetic field sensing element in the magnetic field, said sensing element having an output signal conductor and producing an output signal when the samples are in operative relationship with said at least one sensing element; and
,a signal processor for converting said output signals from said at least one sensing element to provide a signal indicative of the quantity of the target molecules in a sample pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 41, 42, 43, 44, 45)
a code element on said substrate; and
a code reader mounted in position to read said code element when the samples are moved into operative relationship with said at least one sensing element.
-
-
11. The apparatus of claim 1, wherein said at least one sensing element senses the difference in the DC magnetic field caused by the presence of the samples.
-
12. The apparatus of claim 4, wherein said at least one sensing element senses the difference in the DC magnetic field caused by the presence of the samples.
-
13. The apparatus of claim 5, wherein said at least one sensing element senses the difference in the DC magnetic field caused by the presence of the samples.
-
14. The apparatus of claim 1, wherein said signal processor comprises:
-
an amplifier connected to the output of said at least one sensing element;
a balancing stage connected to said amplifier; and
a lock-in stage, the output of which is the signal indicative of the quantity of said target molecules in a sample pattern.
-
-
15. The apparatus of claim 4, wherein said signal processor comprises:
-
an amplifier connected to the output of said at least one sensing element;
a balancing stage connected to said amplifier;
a lock-in stage, the output of which is the signal indicative of the quantity of said target molecules in a sample pattern; and
means for synchronously coupling excitation current to said lock-in stage.
-
-
16. The apparatus of claim 5, wherein said signal processor comprises:
-
an amplifier connected to the output of said at least one sensing element;
a balancing stage connected to said amplifier;
a lock-in stage, the output of which is the signal indicative of the quantity of said target molecules in a sample pattern; and
means for synchronously the said lock-in stage to the sources of excitation current.
-
-
41. The apparatus of claim 1, wherein the DC magnetic field has a strength of 500-1,000 Oersted.
-
42. The apparatus of claim 41, wherein the said at least one sensing element is a Hall sensor.
-
43. The apparatus of claim 2, wherein the DC magnetic field has a strength of 500-1,000 Oersted.
-
44. The apparatus of claim 1, wherein the size of said sensing element is chosen to be about the same size as a sample pattern.
-
45. The apparatus of claim 2, wherein the size of said sensing element is chosen to be about the same size as a sample pattern.
-
17. Apparatus for making quantitative measurements of agglutinations of magnetic particles comprising complexes of non-magnetized, magnetizable particles and target molecules, said apparatus comprising:
-
a substrate configured to receive samples of the agglutinations including unknown quantities of said magnetic particles in defined patterns thereon, the magnetizable particles in the samples being of known size and magnetic characteristics bound to the target molecules;
means for providing a DC magnetic field, the magnetic field producing magnetization in the magnetizable particles when they are in the magnetic field;
magnetic field sensing means in the magnetic field, said sensing means having output signal means and producing an output signal when the samples are in operative relationship with said sensing means; and
,means for converting said output signals from said sensing means to provide a signal indicative of the quantity of the target molecules in a sample pattern. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 46, 47, 50, 51)
means for connecting said sensing means to a source of excitation current;
said sensing means comprises a Hall sensor connected to said means for connecting to the bias excitation current source.
-
-
19. The apparatus of claim 17, wherein said sensing means comprises a magneto-resistive sensor.
-
20. The apparatus of claim 17, wherein said sensing means comprises two Hall sensors, each adapted to connect to a source of bias excitation current to be applied to said sensors.
-
21. The apparatus of claim 20, wherein the excitation current flows through said Hall sensors in series.
-
22. The apparatus of claim 20, wherein the excitation current flows through said Hall sensors in parallel.
-
23. The apparatus of claim 18, wherein the excitation current is an AC excitation current.
-
24. The apparatus of claim 20, wherein the excitation current is an AC excitation current.
-
25. The apparatus of claim 17, and further comprising:
-
a code element on said substrate; and
a code reader mounted in position to read said code element when the samples are moved into operative relationship with said sensing means.
-
-
26. The apparatus of claim 17, wherein said converting means comprises a signal processor having:
-
an amplifier connected to the output of said at least one sensing means;
a balancing stage connected to said amplifier; and
a lock-in stage, the output of which is the signal indicative of the quantity of the target molecules in said samples.
-
-
27. The apparatus of claim 20, wherein said converting means comprises a signal processor having:
-
an amplifier connected to the output of said at least one sensing means;
a balancing stage connected to said amplifier;
a lock-in stage, the output of which is the signal indicative of the quantity of the target molecules in said samples in a pattern; and
means for synchronously coupling excitation current to said lock-in stage.
-
-
46. The apparatus of claim 17, wherein the size of said sensing means is chosen to be about the same size as a sample pattern.
-
47. The apparatus of claim 18, wherein the size of said sensing means is chosen to be about the same size as a sample pattern.
-
50. The apparatus of claim 17, wherein the DC magnetic field has a strength of 500-1,000 Oersted.
-
51. The apparatus of claim 18, wherein the DC magnetic field has a strength of 500-1,000 Oersted.
-
28. A method for quantitatively determining target molecules in a sample pattern, said method comprising:
-
applying at least one sample pattern having unknown quantities of target molecules in a predetermined configuration on a substrate, the sample pattern being comprised of non-magnetized, magnetizable particles of known size and magnetic characteristics coupled to the target molecules to form magnetic bound complex samples;
providing a DC magnetic field;
causing relative motion between the substrate and the magnetic field to place the sample pattern within the magnetic field;
exciting the magnetizable particles in the pattern by means of the DC magnetic field to make them magnetic and thereby cause the magnetic particles to perturb the magnetic field;
sensing the magnetic field changes caused by the presence of the magnetized particles in the magnetic field; and
creating a signal representative of the quantity of target molecules in the field. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 48, 49, 52, 53)
-
Specification