Sample purification on a microfluidic device

Abstract

Sample preparation has long been recognized as a significant barrier to the implementation of macroscopic protocols on microfabricated devices. Macroscopically, such tasks as removing salts, primers and other contaminants are performed by methods involving precipitation, specialized membranes and centrifuges, none of which are readily performed in microfluidic structures. Although some microfluidic systems have been developed for performing sample purification, their complexity may hinder the degree to which they can be implemented. We present a method of microchip-based sample purification that can be performed with even the simplest microfluidic designs. The technique is demonstrated by removing primers from a sample of amplified DNA, leaving only the product DNA. This provides a new sample preparation capability for microfluidic systems.

Selective protein removal and desalting using microchip CE

“…Although several 2D separation systems on chip have been published, combining e.g. sample stacking and CZE [27,34,35], ITP and CZE [12,[18][19][20][30][31][32]36,37], isoelectric focusing (IEF) and CZE [38], open-channel electrochromatography (OCEC) and CZE [17], solid-phase extraction (SPE) and OCEC [39], micellar electrokinetic chromatography (MEKC) and CZE [40], SPE-MEKC [41], or even in-line SPE-CZE-MS [42], only few describe the analysis of intact proteins [12,34,37,38] or protein digests [27,40].…”

Microfluidic Platform for Single Nucleotide Polymorphism Genotyping of the Thiopurine S-Methyltransferase Gene to Evaluate Risk for Adverse Drug Events

“…46 Channels were filled with POP-6 polymer (Applied Biosystems, Foster City, CA) heated to 65°C for 10 minutes. The CE sample loading well is filled with a mixture of 1 l of the digested PCR product, 0.5 l of a fluorescently labeled DNA ladder, GeneScan 500 TAMRA (Applied Biosystems), 1.2 l of HiDi formamide (Applied Biosystems), and 0.3 l of a 1ϫ genetic analysis buffer with ethylenediamine tetraacetic acid (GABE; Applied Biosystems), which was denatured at 96°C for 5 minutes and rapidly cooled to ϳ4°C.…”

“…Sample injection with 0.4 kV (60 seconds) followed by separation at 6 kV (240 seconds) was performed. 46 …”

On-chip HA/SSCP for the detection of hereditary haemochromatosis

“…The analysis programme wrote postscript files for all of the analysed data. More details can be found in the previous work (Footz et al 2001).…”

“…The Microfluidic Tool Kit (lTK, also from Micralyne) was used to manipulate the reagents and DNA upon these microchips. It is comprised of high-voltage electronics, detection optics, optical detection electronics, and software control as described previously (Footz et al 2001). The detection system is a laser-induced fluorescence (LIF) system that provides excitation at a wavelength of 532 nm and detection at 578 nm.…”