Cell concentration and lysate clearance using paramagnetic particles

Abstract

Methods are disclosed for using paramagnetic particles to concentrate or harvest cells. Methods are also disclosed for clearing a solution of disrupted biological material, such as a lysate of cells or a homogenate of mammalian tissue. Methods are also disclosed for using paramagnetic particles to isolate target nucleic acids, such as RNA or DNA, from a solution cleared of disrupted biological material using the same type or a different type of paramagnetic particle. Kits are also disclosed for use with the various methods of the present invention. Nucleic acids isolated according to the present methods and using the present kits are suitable for immediate use in downstream processing, without further purification.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. application Ser. No. 09 / 475,958, filed Dec. 30, 1999, which claims the benefit of U.S. Provisional Application No. 60 / 134,156, filed May 14, 1999, and is a continuation-in-part of U.S. application Ser. No. 09 / 064,449, filed Apr. 22, 1998, now U.S. Pat. No. 6,194,562. This application claims priority to each of these applications and hereby fully incorporates the subject matter of each of these applications.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable. TECHNICAL FIELD [0003] This invention relates generally to the use of magnetically responsive particles, such as magnetically responsive silica gel particles or magnetically responsive ion exchange particles, to harvest or to concentrate cells or biological tissue. This invention also relates to the use of such particles to clear lysates or homogenates of such cells or tissue. This invention relates, furtherm...

AI Technical Summary

Benefits of technology

The present invention is a method of using magnetic particles to process biological material. The methods involve combining magnetic particles with cells or other disrupted biological material, and then isolating the magnetic particle / cell complex or the target nucleic acid from the solution using magnetic force. The methods can be used to isolate target nucleic acids from a variety of contaminants, including agarose and non-target nucleic acids. The invention also includes kits with magnetic particles and solutions for practicing the methods. The technical effects of the invention include improved efficiency and accuracy in isolating target nucleic acids from biological materials.

Problems solved by technology

Unfortunately, neither filtration nor centrifugation is amenable to automation.

However, for reasons given above, neither means of clearing a lysate solution is amenable to automation.

Unfortunately, the type of silica-based solid phases described above all require one use centrifugation or filtration to perform the various isolation steps in each method, limiting the utility of such solid phases in automated systems.

Each additional component or solution used in the nucleic acid isolation procedure adds to the risk of contamination of the isolated end product by nucleases, metals, and other deleterious substances.

Nucleic acid material tends to bind very tightly to glass, however, so that it can be difficult to remove once bound thereto.

It is also difficult to produce such particles with a sufficiently uniform and concentrated magnetic capacity to ensure rapid and efficient isolation of nucleic acid materials bound thereto.

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