Rate of Mixing Controls Rate and Outcome of Autocatalytic Processes: Theory and Microfluidic Experiments with Chemical Reactions and Blood Coagulation

Pompano, Rebecca R.; Li, Hung‐Wing; Ismagilov, Rustem F.

doi:10.1529/biophysj.108.129486

Cited by 30 publications

(27 citation statements)

References 86 publications

(142 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This SlipChip enables similar control of surface chemistry as in previously developed plug-based microfluidic systems because of the use of the fluorinated lubricating fluid 34-36. Assays with enzymes,37 blood,38,39 and cells32,34 have been performed in plug-based systems, so we expect that similar assays can be performed in SlipChip. We also expect this approach to be useful for analysis of samples obtained by the chemistrode 40-43…”

Section: Resultsmentioning

confidence: 98%

User-Loaded SlipChip for Equipment-Free Multiplexed Nanoliter-Scale Experiments

Ismagilov

2009

J. Am. Chem. Soc.

View full text Add to dashboard Cite

This paper describes a microfluidic approach to perform multiplexed nanoliter-scale experiments by combining a sample with multiple different reagents, each at multiple mixing ratios. This approach employs a user-loaded, equipment-free SlipChip. The mixing ratios, characterized by diluting a fluorescent dye, could be controlled by the volume of each of the combined wells. The SlipChip design was validated on ~12 nL scale by screening the conditions for crystallization of glutaryl-CoA dehydrogenase from Burkholderia pseudomallei against 48 different reagents; each reagent was tested at 11 different mixing ratios, for a total of 528 crystallization trials. The total consumption of the protein sample was ~ 10 μL. Conditions for crystallization were successfully identified. The crystallization experiments were successfully scaled up in well plates using the conditions identified in the SlipChip. Crystals were characterized by X-ray diffraction and provided a protein structure in a different space group and at a higher resolution than the structure obtained by conventional methods. In this work, this user-loaded SlipChip has been shown to handle reliably fluids of diverse physicochemical properties, such as viscosities and surface tensions. Quantitative measurements of fluorescent intensities and high-resolution imaging were straighforward to perform in these glass SlipChips. Surface chemistry was controlled using fluorinated lubricating fluid, analogous to the fluorinated carrier fluid used in plug-based crystallization. Thus, we expect this approach to be valuable in a number of areas beyond protein crystallization, especially those areas where droplet-based microfluidic systems have demonstrated successes, including measurements of enzyme kinetics and blood coagulation, cell-based assays, and chemical reactions.

show abstract

Section: Resultsmentioning

confidence: 98%

User-Loaded SlipChip for Equipment-Free Multiplexed Nanoliter-Scale Experiments

Ismagilov

2009

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…57,59 This concentration of RfOEG was previously used to prevent droplets of clotted and unclotted human plasma from adhering to a Teflon-coated PDMS channel. 60 In addition to 1 mg/mL BSA solution, we also tested spontaneous flow of a serum-free cell culture medium (AIM-V, Gibco) and fresh whole human blood (citrated). These solutions were loaded carefully onto the chip to avoid pushing them into the gap, and flowing was initiated by slipping.…”

Section: Resultsmentioning

confidence: 99%

Control of Initiation, Rate, and Routing of Spontaneous Capillary-Driven Flow of Liquid Droplets through Microfluidic Channels on SlipChip

et al. 2012

Self Cite

View full text Add to dashboard Cite

This paper describes the use of capillary pressure to initiate and control the rate of spontaneous liquid-liquid flow through microfluidic channels. In contrast to flow driven by external pressure, flow driven by capillary pressure is dominated by interfacial phenomena and is exquisitely sensitive to the chemical composition and geometry of the fluids and channels. A step-wise change in capillary force was initiated on a hydrophobic SlipChip by slipping a shallow channel containing an aqueous droplet into contact with a slightly deeper channel filled with immiscible oil. This action induced spontaneous flow of the droplet into the deeper channel. A model predicting the rate of spontaneous flow was developed based on the balance of net capillary force with viscous flow resistance, using as inputs the liquid-liquid surface tension, the advancing and receding contact angles at the three-phase aqueous-oil-surface contact line, and the geometry of the devices. The impact of contact angle hysteresis, the presence or absence of a lubricating oil layer, and adsorption of surface-active compounds at liquid-liquid or liquid-solid interfaces were quantified. Two regimes of flow spanning a 104-fold range of flow rates were obtained and modeled quantitatively, with faster (mm/s) flow obtained when oil could escape through connected channels as it was displaced by flowing aqueous solution, and slower (micrometer/s) flow obtained when oil escape was mostly restricted to a μm-scale gap between the plates of the SlipChip (“dead-end flow”). Rupture of the lubricating oil layer (reminiscent of a Cassie-Wenzel transition) was proposed as a cause of discrepancy between the model and the experiment. Both dilute salt solutions and complex biological solutions such as human blood plasma could be flowed using this approach. We anticipate that flow driven by capillary pressure will be useful for design and operation of flow in microfluidic applications that do not require external power, valves, or pumps, including on SlipChip and other droplet- or plug-based microfluidic devices. In addition, this approach may be used as a sensitive method of evaluating interfacial tension, contact angles and wetting phenomena on chip.

show abstract

“…Pompano and co-workers have used the Damkçhler number to predict the outcome of autocatalytic reactions in segmented flow systems. [16] Tuning Reaction, Fluidic and System Parameters to Maximize Product Formation Rates…”

Section: Discussionmentioning

confidence: 99%

Miniaturizing Biocatalysis: Enzyme‐Catalyzed Reactions in an Aqueous/Organic Segmented Flow Capillary Microreactor

2011

View full text Add to dashboard Cite

A segmented flow capillary microreactor was used to perform the enzyme-catalyzed conversion of 1-heptaldehyde to 1-heptanol in a two liquidliquid phase system. These reactor formats are established for chemical reactions but so far data describing the relevant system parameters for enzymatic catalysis are lacking. This work now addresses the impact of important parameters such as capillary diameter, flow velocity, phase ratio, and enzyme as well as substrate concentration on the performance of the enzymatic reaction under segmented flow conditions. All key parameters governing reaction performance have been correlated in a novel operational window for an easy assessment of the various system constraints.

show abstract

Rate of Mixing Controls Rate and Outcome of Autocatalytic Processes: Theory and Microfluidic Experiments with Chemical Reactions and Blood Coagulation

Cited by 30 publications

References 86 publications

User-Loaded SlipChip for Equipment-Free Multiplexed Nanoliter-Scale Experiments

User-Loaded SlipChip for Equipment-Free Multiplexed Nanoliter-Scale Experiments

Control of Initiation, Rate, and Routing of Spontaneous Capillary-Driven Flow of Liquid Droplets through Microfluidic Channels on SlipChip

Miniaturizing Biocatalysis: Enzyme‐Catalyzed Reactions in an Aqueous/Organic Segmented Flow Capillary Microreactor

Contact Info

Product

Resources

About