DNA aptamers for eosinophil peroxidase detection
This disclosure relates to DNA aptamers that bind eosinophil peroxidase, including uses thereof, such as in eosinophil peroxidase detection assays. Also provided is a method for detecting the presence of eosinophil peroxidase in a sample, using the DNA aptamers that bind eosinophil peroxidase. Further provided is a kit for detecting the presence of eosinophil peroxidase in a sample, using the DNA aptamers that bind eosinophil peroxidase.
1 . A DNA aptamer that binds eosinophil peroxidase, wherein the aptamer comprises the sequence of SEQ ID NO: 30, 9, or 36.
2 . A DNA aptamer that binds eosinophil peroxidase, wherein the aptamer consists of the sequence of SEQ ID NO: 30, 9, or 36.
3 . The aptamer of claim 1 , further comprising an immobilization linker.
4 . The aptamer of claim 3 , wherein the immobilization linker is biotin.
5 . An aptamer probe comprising the aptamer of claim 1 and a detectable label.
6 . The aptamer probe of claim 5 , wherein the detectable label comprises a fluorescent, a colorimetric or other optical probe or electrochemical moiety.
7 . A method for detecting the presence of eosinophil peroxidase in a sample, the method comprising:
a) contacting the sample with the aptamer probe of claim 5 , and
b) detecting a signal generated from binding of the aptamer with the eosinophil peroxidase,
wherein detecting the signal indicates the presence of the eosinophil peroxidase in the sample.
8 . The method of claim 7 , further comprising dispersing the sample in a buffer solution comprising about 2 mM dithiothreitol before step a), optionally the buffer solution comprises HEPES.
9 . The method of claim 8 , wherein the sample is a sputum sample.
10 . A method for detecting the presence of eosinophil peroxidase in a sample, the method comprising:
a) contacting the sample with an immobilized aptamer of claim 1 in a first buffer solution;
b) allowing the immobilized aptamer to bind to the eosinophil peroxidase to form an immobilized aptamer-eosinophil peroxidase complex;
c) transferring the immobilized aptamer-eosinophil peroxidase complex to a second buffer solution;
d) adding a solution of H 2 O 2 and 3,3′,5,5′-tetramethylbenzidine to the second buffer solution; and
e) detecting a colorimetric signal;
wherein detecting the colorimetric signal indicates the presence of eosinophil peroxidase in the sample.
11 . The method of claim 10 , further comprising, before step c), washing the immobilized aptamer-eosinophil peroxidase complex with a washing buffer, optionally washing up to 3 times before step c).
12 . The method of claim 10 , further comprising dispersing the sample in a buffer solution comprising about 2 mM dithiothreitol before step a), optionally the buffer solution comprises HEPES.
13 . The method of claim 10 , wherein the sample is a sputum sample.
14 . A kit for detecting eosinophil peroxidase, wherein the kit comprises the aptamer of claim 1 and instructions for use of the kit.
15 . The kit of claim 14 , further comprising a solution comprising H 2 O 2 and 3,3′,5,5′-tetramethylbenzidine.
16 . The kit of claim 14 , further comprising a buffer solution for dispersing a sample, wherein the buffer solution comprises 2 mM dithiothreitol, optionally the buffer solution comprises HEPES.
17 . The kit of claim 14 , wherein the kit further comprises one or more buffers.