Microfluidic device with diffusion between adjacent lumens

Abstract

A microfluid method is provided that comprises: delivering a first fluid to a first lumen of a microfluidic device and a second, different fluid to a second lumen of the microfluidic device, the first and second lumens sharing a common wall which allows for diffusion between the lumens over at least a portion of the length of the lumens; and having the first and second fluids diffuse between the first and second lumens.

Description

RELATED APPLICATIONS [0001] This application is a continuation of co-pending U.S. patent application Ser. No. 10 / 060,872 filed Jan. 29, 2002, now allowed, which is a continuation in part of U.S. patent application Ser. No. 09 / 877,405 filed Jun. 8, 2001, which issued on Apr. 13, 2004, as U.S. Pat. No. 6,719,840, each of which are incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates to microfluidic devices and methods. DESCRIPTION OF RELATED ART [0003] Traditional methods for crystal growth and crystallization are highly labor intensive and require significant quantities of material to evaluate and optimize crystal growth conditions. Examples of these methods include the free interface diffusion method (Salemme, F. R. (1972) Arch. Biochem. Biophys. 151:533-539), vapor diffusion in the hanging or sitting drop method (McPherson, A. (1982) Preparation and Analysis of Protein Crystals, John Wiley and Son, New York, pp 82-127), and liquid dialysis (B...

AI Technical Summary

Benefits of technology

The present invention provides microfluidic devices, methods, and kits that have various features and capabilities. One feature is the use of a card shaped substrate with microvolumes and grooves that have overlapping lateral footprints, which can be used for various experiments and analyses. Another feature is the use of a plurality of microvolumes within a microfluidic device, where the microvolumes have different crystallization conditions, allowing for the identification of the optimal conditions for crystallization of a material. The invention also provides a method for determining crystallization conditions by using a microfluidic device with one or more lumens and transporting different crystallization samples within the lumens. Overall, the invention provides various tools and methods for utilizing microfluidic devices for various crystallization experiments and analyses.

Problems solved by technology

Traditional methods for crystal growth and crystallization are highly labor intensive and require significant quantities of material to evaluate and optimize crystal growth conditions.

The process of growing crystals with high diffraction quality is time-consuming and involves trial-and-error experiment on multiple solution variables such as pH, temperature, ionic strength, and specific concentrations of salts, organic additives, and detergents.

In addition, the amount of highly purified protein is usually limited, multi-dimensional trials on these solution conditions are unrealistic, labor-intensive and costly.

Existing crystallization, such as hanging drop, sitting drop, dialysis and other vapor diffusion methods have the limitation that the material for analysis and the crystallization medium are exposed to the environment for some time.

This causes smaller volumes to be more susceptible to evaporation during the initial creation of the correct mixture and during the initial period after the volume has been set up.

Moreover, typical methods expose the sample drop to the environment for a duration of seconds to minutes.

Small variability in the rate that samples are made can cause significant variations in the production of crystals.

Prior methods fail to reduce the problems of convection currents under 1 g such as those described in U.S. Pat. No. 4,886,646, without the large expenditure of resources or in methods that complicate crystal analysis.

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