Aptamer and detection method for C-reactive protein
An aptamer specifically binding to C-reactive protein (CRP) is provided. The aptamer includes a following nucleotide sequence: 5′-angngggngnntgnnt-3′, wherein n is a nucleotide selected from a, t, c and g.
1. An aptamer specifically binding to a C-reactive protein and comprising a following nucleotide sequence:
(SEQ ID NO: 4)
5′-ggcaggaagacaaacacgatgggggggtatgatttgatgtggttgtt
gcatgatcgtggtctgtggtgctgt-3′.
2. The aptamer as claimed in claim 1 , wherein a binding affinity (Kd) between the aptamer and the C-reactive protein ranges from 0.3 nanomole (nM) to 30 nM.
3. The aptamer as claimed in claim 1 , having a 5′ end modified by a thiol group, a biotin, a fluorescent label, or an enzyme.
4. The aptamer as claimed in claim 1 , comprising 72 to 80 nucleotides.
5. A detection method for a C-reactive protein, adapted for detecting the C-reactive protein in a sample, the detection method comprising: providing the aptamer as claimed in claim 1 ; mixing the sample and the aptamer, such that the C-reactive protein in the sample and the aptamer bind to form a C-reactive protein-aptamer; anddetecting the C-reactive protein or the aptamer in the C-reactive protein-aptamer.
6. The detection method for the C-reactive protein as claimed in claim 5 , wherein the aptamer is labeled with a fluorescent label or a luminescent label.
7. A detection method for a C-reactive protein, adapted for detecting the C-reactive protein in a sample, the detection method comprising: providing a plurality of beads non-covalently bonded to the aptamer as claimed in claim 1 respectively; mixing the beads and the sample, such that the aptamers on the beads bind with the C-reactive proteins in the sample; adding C-reactive protein antibodies to the sample mixed with the beads, such that the C-reactive protein antibodies bind with the C-reactive proteins bound on the beads;
removing the unbound C-reactive protein antibodies; and
detecting the C-reactive protein antibodies bound to the beads through the C-reactive proteins.
8. The detection method for the C-reactive protein as claimed in claim 7 , wherein the aptamer and the bead are non-covalently bonded through a biotin-streptavidin interaction.