Method and apparatus for reading an assay using low resolution detection
A method of reading an assay includes illuminating a substrate. The substrate includes a sensitive region. The method also includes detecting whether the substrate was exposed to an analyte of interest. The detecting includes using low resolution detection and a priori data about the sensitive region to determine whether a characteristic of a first portion of the illumination returned from the sensitive region differs from a characteristic of a second portion of the illumination returned from the substrate outside the sensitive region.
1 . A method of reading an assay, the method comprising:
illuminating a substrate, the substrate comprising a sensitive region; and
detecting whether the substrate was exposed to an analyte of interest, the detecting comprising using low resolution detection and a priori data about the sensitive region to determine whether a characteristic of a first portion of the illumination returned from the sensitive region differs from a characteristic of a second portion of the illumination returned from the substrate outside the sensitive region.
2 . The method of claim 1 , further comprising:
detecting a shape of the sensitive region based upon a combination of the characteristic of the first portion of the illumination, the characteristic of the second portion of the illumination, and a characteristic of a combination of the first portion of the illumination and the second portion of the illumination.
3 . The method of claim 2 , further comprising:
detecting signal level in a first pixel to determine the characteristic of the first portion,
detecting signal level in a second pixel to determine the characteristic of the second portion, and
detecting signal level in a third pixel to determine the characteristic of the combination of the first portion and the second portion.
4 . The method of claim 2 , further comprising:
detecting spectral intensity to determine the characteristic of the first portion,
detecting spectral intensity to determine the characteristic of the second portion, and
detecting spectral intensity to determine the characteristic of the combination of the first portion and the second portion.
5 . The method of claim 2 , further comprising:
moving the substrate, and
sequentially detecting the first portion of the illumination, the second portion of the illumination, and the combination of the first portion of the illumination and the second portion of the illumination during the moving.
6 . The method of claim 2 , further comprising:
detecting the first portion of the illumination, the second portion of the illumination, and the combination of the first portion of the illumination and the second portion of the illumination in parallel.
7 . The method of claim 1 , further comprising:
detecting signal level in a first pixel to determine the characteristic of the first portion, and
detecting signal level in a second pixel to determine the characteristic of the second portion.
8 . The method of claim 1 , further comprising:
detecting filtered signal level to determine the characteristic of the first portion, and
detecting filtered signal level to determine the characteristic of the second portion.
9 . The method of claim 1 , further comprising:
moving the substrate, and
sequentially detecting the first portion of the illumination and the second portion of the illumination during the moving.
10 . The method of claim 1 , further comprising:
detecting the first portion of the illumination and the second portion of the illumination in parallel.
11 . An apparatus for reading an assay of a sample deposited on a substrate having a sensitive region to determine whether an analyte of interest was included in the sample, the apparatus comprising:
an illuminator arranged to illuminate the substrate;
a low resolution detector arranged to detect illumination returned from the substrate; and
an analyzer coupled to the low resolution detector and operating in response to a priori data about the sensitive region to determine whether the substrate was exposed to the analyte of interest by analyzing the detected illumination to determine whether a characteristic of a first portion of the illumination returned from the sensitive region differs from a characteristic of a second portion of the illumination returned from the substrate outside the sensitive region.
12 . The apparatus of claim 11 , the low resolution detector comprising two detectors.
13 . The apparatus of claim 11 , wherein:
the low resolution detector comprises three detectors, and
the analyzer further determines a shape of the sensitive region based upon the characteristic of the first portion of the illumination returned from the sensitive region, the characteristic of the second portion of the illumination returned from the substrate outside the sensitive region, and a characteristic of a combination of the first portion of the illumination and the second portion of the illumination.
14 . The apparatus of claim 11 , wherein the low resolution detector comprises a one dimensional array of detectors.
15 . The apparatus of claim 14 , wherein:
the apparatus further comprises a mover operating to move the substrate with respect to the low resolution detector; and
the low resolution detector sequentially detects the first portion of the illumination and the second portion of the illumination as the substrate moves.
16 . The apparatus of claim 11 , wherein the low resolution detector comprises a two dimensional array of detectors.
17 . The apparatus of claim 16 , wherein the low resolution detector detects the first portion of the illumination and the second portion of the illumination in parallel.
18 . A method of reading an assay, the method comprising:
illuminating a substrate, the substrate comprising sensitive regions; and
detecting whether the substrate was exposed to analytes of interest, the detecting comprising using low resolution detection and a priori data about the sensitive regions to determine whether one or both of a characteristic of a first portion of the illumination returned from one of the sensitive regions and a characteristic of a second portion of the illumination returned from another of the sensitive regions differs from a characteristic of a third portion of the illumination returned from the substrate outside the sensitive regions.
19 . The method of claim 18 , wherein the detecting comprises detecting the first portion, the second portion, and the third portion in parallel.
20 . The method of claim 18 , wherein the detecting comprises sequentially detecting the first portion, the second portion, and the third portion sequentially.
21 . The method of claim 20 , wherein:
the low resolution detector comprises an array of detectors;
the sensitive regions have respective shapes on the substrate different from each other, and
the detecting comprises detecting respective characteristics of combinations of the first portion, the second portion, and the third portion of the illumination returned from the substrate to determine the shapes of the respective sensitive regions.
22 . The method of claim 18 , wherein:
the method further comprises moving the sensitive regions; and
the detecting further comprises sequentially detecting the first portion, the second portion, and the third portion during the moving.
23 . An apparatus for reading an assay of a sample deposited on a substrate having sensitive regions to determine whether a respective analyte of interest was included in the sample, the apparatus comprising:
an illuminator arranged to illuminate the substrate;
a low resolution detector arranged to detect illumination returned from the substrate and comprising an array of detectors; and
an analyzer coupled to the low resolution detector and operating in response to a priori data about the sensitive regions to determine whether at least one of the sensitive regions was exposed to the analyte of interest by analyzing the detected characteristics to determine whether one or both of a characteristic of a first portion of the illumination returned from one of the sensitive regions and a characteristic of a second portion of the illumination returned from another of the sensitive regions differs from a characteristic of a third portion of the illumination returned from the substrate outside the sensitive regions.
24 . The apparatus of claim 23 , wherein the low resolution detector sequentially detects respective characteristics of the first portion, the second portion, and the third portion of the illumination returned from the substrate to determine shapes of the sensitive regions.
25 . The apparatus of claim 24 , wherein:
the apparatus further comprises a mover operating to move the substrate with respect to the low resolution detector; and
the low resolution detector sequentially detects the respective portions of the illumination as the substrate moves.
26 . The apparatus of claim 23 , wherein the low resolution detector detects the respective portions of the illumination in parallel.
27 . An apparatus for reading an assay of a sample deposited on a substrate having a sensitive region to determine whether an analyte of interest was included in the sample, the apparatus comprising:
an illuminator arranged to illuminate the substrate;
a low resolution detector arranged to detect illumination returned from the substrate; and
a processor coupled to the low resolution detector and operating in response to a priori data about the sensitive region to determine whether the substrate was exposed to the analyte of interest by executing a statistical pattern recognition function to analyze the detected illumination to determine whether a characteristic of a first portion of the illumination returned from the sensitive region differs from a characteristic of a second portion of the illumination returned from the substrate outside the sensitive region.
28 . The apparatus of claim 27 , wherein the low resolution detector comprises an array of detectors.