Methods and Compositions for Efficient Nucleic Acid Sequencing

Abstract

Disclosed are novel methods and compositions for rapid and highly efficient nucleic acid sequencing based upon hybridization with two sets of small oligonucleotide probes of known sequences. Extremely large nucleic acid molecules, including chromosomes and non-amplified RNA, may be sequenced without prior cloning or subcloning steps. The methods of the invention also solve various current problems associated with sequencing technology such as, for example, high noise to signal ratios and difficult discrimination, attaching many nucleic acid fragments to a surface, preparing many, longer or more complex probes and labelling more species.

Description

[0001] The present application is a continuation-in-part of co-pending U.S. patent application Ser. No. 08 / 303,058, filed Sep. 8, 1994; which is a continuation-in-part of U.S. patent application Ser. No. 08 / 127,420, filed Sep. 27, 1993; the entire text and figures of which disclosures are specifically incorporated herein by reference without disclaimer.[0002] The U.S. Government owns rights in the present invention pursuant to Department of Energy grant LDRD 03235 and Contract No. W-31-109-ENG-38 between the U.S. Department of Energy and The University of Chicago, representing Argonne National Laboratory.BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention generally relates to the field of molecular biology. The invention particularly provides novel methods and compositions to enable highly efficient sequencing of nucleic acid molecules. The methods of the invention are suitable for sequencing long nucleic acid molecules, including chromosomes an...

AI Technical Summary

Benefits of technology

[0011] The present invention seeks to overcome these and other drawbacks inherent in the prior art by providing new methods and compositions for the sequencing of nucleic acids. The novel techniques described herein have been generally termed Format 3 by the inventors and represent marked improvements over the existing Format 1 and Format 2 SBH methods. In the Format 3 sequencing provided by the invention, nucleic acid sequences are determined by means of hybridization with two sets of small oligonucleotide probes of known sequences. The methods of the invention allow high discriminatory sequencing of extremely large nucleic acid molecules, including chromosomal material or RNA, without prior cloning, subcloning or amplification. Furthermore, the present methods do not require large numbers of probes, the complex synthesis of longer probes, or the labelling of a complex mixture of nucleic acids segments.

[0027] (b) contacting the primary complexes with the set of labelled oligonucleotide probes in solution under hybridization conditions effective to allow probes with complementary sequences to hybridize to a non-hybridized or free fragment sequence, thereby forming secondary complexes wherein the fragment is hybridized to both an attached (immobilized) probe and a labelled probe;

[0045] Next one would detect the secondary complexes by detecting the presence of the label and identify sequences of length F+P from the nucleic acid fragments in the secondary complexes by combining the known sequences of the hybridized immobilized and labelled probes. Stretches of the sequences of length F+P that overlap would then be identified, thereby allowing the complete nucleic acid sequence of the molecule to be reconstructed or assembled from the overlapping sequences determined.

Problems solved by technology

However, progress in this area is generally both slow and costly.

Both methods are time-consuming and laborious.

However, although SBH has the potential for increasing the speed with which nucleic acids can be sequenced, all current SBH methods still suffer from several drawbacks.

Unfortunately, both of these SBH formats have several limitations, particularly the requirement for prior DNA cloning steps.

In Format 1, other significant problems include attaching the various nucleic acid pieces to be sequenced to the solid surface support or preparing a large set of longer probes.

In Format 2, major problems include labelling the nucleic acids of unknown sequence, high noise to signal ratios that generally result, and the fact that only short sequences can be determined.

Further problems of Format 2 include the secondary structure formation that prevents access to some targets and the different conditions that are necessary for probes with different GC contents.

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