A bisulfite treatment and PCR-free global DNA methylation detection method using electrochemical enzymatic signal engagement

Copyright © 2018 Elsevier B.V. All rights reserved..

In this paper we report on a bisulfite treatment and PCR amplification-free method for sensitive and selective quantifying of global DNA methylation. Our method utilizes a three-step strategy that involves (i) initial isolation and denaturation of global DNA using the standard isolation protocol and direct adsorption onto a bare gold electrode via gold-DNA affinity interaction, (ii) selective interrogation of methylation sites in adsorbed DNA via methylation-specific 5mC antibody, and (iii) subsequent signal enhancement using an electrochemical-enzymatic redox cycling reaction. In the redox cycling reaction, glucose oxidase (GOx) is used as an enzyme label, glucose as a substrate and ruthenium complex as a redox mediator. We initially investigated the enzymatic properties of GOx by varying glucose and ruthenium concentration to delineate the redox cyclic mechanism of our assay. Because of the fast electron transfer by ruthenium (Ru) complex and intrinsic signal amplification from GOx label, this method could detect as low as 5% methylation level in 50 ng of total DNA input. Moreover, the use of methylation-specific 5mC antibody conjugated GOx makes this assay relatively highly selective for DNA methylation analysis. The data obtained from the electrochemical response for different levels of methylation showed excellent interassay reproducibility of RSD (relative standard deviation) < 5% for n = 3. We believe that this inexpensive, rapid, and sensitive assay will find high relevance as an alternative method for DNA methylation analysis both in research and clinical platforms.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:126

Enthalten in:

Biosensors & bioelectronics - 126(2019) vom: 01. Feb., Seite 102-107

Sprache:

Englisch

Beteiligte Personen:

Bhattacharjee, Ripon [VerfasserIn]
Moriam, Sofia [VerfasserIn]
Nguyen, Nam-Trung [VerfasserIn]
Shiddiky, Muhammad J A [VerfasserIn]

Links:

Volltext

Themen:

7440-57-5
7UI0TKC3U5
9007-49-2
Bisulfite free
DNA
EC 1.1.3.4
Electrochemistry
Enzymatic redox cyclic reaction
Global DNA
Glucose Oxidase
Glucose oxidase
Gold
Hydrogen sulfite
Journal Article
OJ9787WBLU
Ruthenium
Sulfites

Anmerkungen:

Date Completed 15.04.2019

Date Revised 15.04.2019

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.bios.2018.10.020

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM290292786