无码人妻久久一区二区三区免费丨,扒开美女同学的粉嫩小泬,国产一区二区三区四五区,久久精品国产大片免费观看

Junhong Chen, et al.Aptamer-based cell-free detection system to detect target protein, Synthetic and Systems Biotechnology,Volume 6, Issue 3, September 2021, Pages 209-215

Abstract
Biomarkers of disease, especially protein, show great potential for diagnosis and prognosis. For detecting a certain protein, a binding assay implementing antibodies is commonly performed. However, antibodies are not thermally stable and may cause false-positive when the sample composition is complicated. In recent years, a functional nucleic acid named aptamer has been used in many biochemical analysis cases, which is commonly selected from random sequence libraries by using the systematic evolution of ligands by exponential enrichment (SELEX) techniques. Compared to antibodies, the aptamer is more thermal stable, easier to be modified, conjugated, and amplified. Herein, an Aptamer-Based Cell-free Detection (ABCD) system was proposed to detect target protein, using epithelial cell adhesion molecule (EpCAM) as an example. We combined the robustness of aptamer in binding specificity with the signal amplification ability of CRISPR-Cas12a′s trans-cleavage activity in the ABCD system. We also demonstrated that the ABCD system could work well to detect target protein in a relatively low limit of detection (50–100 nM), which lay a foundation for the development of portable detection devices. This work highlights the superiority of the ABCD system in detecting target protein with low abundance and offers new enlightenment for future design and development.

摘要
疾病的生物標志物，尤其是蛋白質，在診斷和預后方面顯示出巨大的潛力。為了檢測某種蛋白質，通常會進行抗體結合試驗。然而，抗體不具有熱穩(wěn)定性，當樣品成分復雜時，可能導致假陽性。近年來，一種稱為適體的功能性核酸已被用于許多生化分析案例中，該核酸通常是通過指數(shù)富集（SELEX）技術利用配體的系統(tǒng)進化從隨機序列庫中選擇的。與抗體相比，適配子更熱穩(wěn)定，易于修飾、接合和擴增。在此，以上皮細胞粘附分子（EpCAM）為例，提出了一種基于適體的無細胞檢測（ABCD）系統(tǒng)來檢測目標蛋白。我們將適配子結合特異性的穩(wěn)健性與ABCD系統(tǒng)中CRISPR-Cas12a的反式切割活性的信號放大能力相結合。我們還證明了ABCD系統(tǒng)能夠很好地檢測目標蛋白，其檢測范圍相對較低（50～100 nm），為便攜式檢測設備的研制奠定了基礎。這項工作突出了ABCD系統(tǒng)在檢測低豐度目標蛋白方面的優(yōu)勢，并為未來的設計和開發(fā)提供了新的啟示。

本研究所采用鏈霉親和素磁珠 http://m.5000js.com/Product/8271042221.html