Development of simple and efficient Lab-on-a-Disc platforms for automated chemical cell lysis

Abstract

Cell lysis is the most important first step for molecular biology and diagnostic testing. Recently, microfluidic systems have attracted considerable attention due to advantages associated with automation, integration and miniaturization, especially in resource-limited settings. In this work, novel centrifugal microfluidic platforms with new configurations for chemical cell lysis are presented. The developed systems employ passive form of pneumatic and inertial forces for effective mixing of lysis reagents and cell samples as well as precise fluidic control. Characterizations of the developed Lab-on-a-Discs (LoaDs) have been conducted with dyed deionized (DI) waters and white blood cells (WBCs) to demonstrate the suitability of the proposed systems in terms of mixing, fluidic control and chemical cell lysis. By making comparison between the results of a well-established manual protocol for chemical cell lysis and the proposed chemical cell lysis discs, it has been proved that the developed systems are capable of realizing automated cell lysis with high throughput in terms of proper values of average DNA yield (ranging from 20.6 to 29.8 ng/µl) and purity (ranging from 1.873 to 1.907) as well as suitability of the released DNA for polymerase chain reaction (PCR). By considering the manual chemical lysis protocol as a reference, the efficiency of the LoaDs has been determined 95.5% and 91% for 10 min and 5 min lysis time, respectively. The developed LoaDs provide simple, efficient, and fully automated chemical cell lysis units, which can be easily integrated into operational on-disc elements to obtain sample-to answer settings systems.

Liquid Mixing Evaluated Using Entropy in a Lab-on-a-disc Platform

“…We used the Euler force to mix the liquids. This force produces acceleration and deceleration and is proportional to the time derivative of the angular velocity vector ω as follows: (11,16,18) Euler…”

“…(1)(2)(3)(4)(5)(6)(7)(8) Recently, the lab-on-a-disc (LOD) has attracted much attention owing to its unique features such as simultaneous multi-item inspection, liquid transfer by centrifugal force, isolation from an external liquid transfer mechanism by a confinement system, and suppression of waste liquid by this isolation. (9)(10)(11)(12)(13)(14)(15)(16)(17)(18) These multiple superior features of LODs can be used in commercial immunoassay systems. (19)(20)(21)(22)(23) Diagnostic devices using LODs have already been released by some companies such as Roche, (20) Abaxis, (21) Samsung Healthcare, (22) and Sysmex.…”

“…Quantitative evaluation of liquid mixing typically uses an approach based on the standard deviation. (16,18) This method is known as Lacey mixing evaluation and is often used to determine the mixing degree of powders and granules. (24) The technique compares the statistical distribution of measured data with the statistical variances of perfectly mixed and completely separated states.…”

Migration Behavior of Low-Density Particles in Lab-on-a-Disc Devices: Effect of Walls

“…In addition to the Archimedes buoyancy (3) and the inertial forces (4) to (6), the Stokes drag force:…”

“…A wide range of applications including clinical chemistry, immunoassay, cell analysis [5,6], and nucleic acid tests [7][8][9], could be demonstrated on a spinning disc [10]. Typical examples of applications of these LOD platforms are sample-to-answer systems for biomedical point-of-care and global diagnostics [11], liquid handling automation for the life sciences (e.g., concentration/purification and amplification of DNA/RNA from a range of bio-samples), process analytical techniques and cell line development for biopharma as well as monitoring the environment, infrastructure, industrial processes and agrifood [12,13].…”