Patent Application
20130157885
1. Field
This specification relates to the field of molecular biology and, more specifically, to methods and systems for selectively analyzing particular alleles of a gene or genes, and applications thereof.
2. Description of the Related Art
Genes are determined to be either “wild-type” or “mutant” based upon variations in a particular gene's sequence of nucleotide bases. The wild-type gene is generally the first identified sequence of a particular gene or the most commonly occurring sequence of a particular gene. A mutant is any gene that has a sequence that varies by at least one nucleic acid base from the sequence of the wild-type gene. There may be one or many mutations for any particular gene and there often is more than one mutation for any particular gene. In certain cases it is important to identify particular mutations for particular genes. The mutations in these cases are generally inherited through and occur in all the somatic cells of an organism.
Germline mutations are inherited and are present in all cells within the organism, and as a result homozygous wild-type or mutant sequences will be present in 100% of the total DNA of that organism, and heterozygous sequences will generally be present in 50% of the total DNA of that organism. In contrast, somatic mutations occur in individual cells in the organism and may occur at any time during the lifetime of that particular organism. As a result, there will be a heterozygous genotype within the cell and its progeny. Often, DNA containing the mutation will represent extremely small percentages of the total DNA from the entire specimen, and may be as low as or less than 1%. This very small incidence of the mutation may not be selectively noticeable using classical molecular biological techniques used for allelic analysis.
Therefore systems and method that can selectively identify only particular alleles in a mixture of nucleic acids purified from a sample of cells from a particular single organism and then analyze those samples for particular mutations of interest would be very useful for researchers and clinical professionals.
In accordance with the foregoing objects and advantages are described methods and systems for selectively analyzing particular alleles of a gene or genes, and applications thereof.
According to one aspect, a method for selectively amplifying a target DNA sequence in the presence of non-target DNA sequence in a sample, the method comprising: (i) contacting an oligonucleotide system with the sample under hybridization conditions to form a reaction mixture, the oligonucleotide system including a forward primer and a reverse primer, wherein one of the forward or reverse primer is modified to preferentially increase hybridization between the primer and the target sequence, the modification comprising a modified 3′ terminal nucleotide; (ii) cycling the oligonucleotide system so that, if the target DNA sequence is present in the sample, the forward primer and the reverse primer hybridize to the target DNA sequence and the reaction mixture results in a first amplified product; and (ii) detecting the first amplified product, wherein the detecting step comprises use of a target DNA probe component for detecting the target DNA sequence, the target DNA probe component comprising a first modification, wherein the first modification preferentially increases hybridization between the target DNA probe component and the first amplified product.
According to a second aspect is the above method, wherein the modified 3′ terminal nucleotide is selected from the group consisting of locked nucleic acid, cLNA, bridged nucleic acid, zip nucleic acid, minor groove binder, peptide nucleic acid, and combinations thereof.
According to a second aspect is the above method, the modified primer further comprises one or more additional modified nucleotides.
According to a third aspect is the above method, wherein the modified primer comprises the oligonucleotide sequence 5′-XYZ-3′, wherein: (i) X comprises one or more biotin groups; (ii) Y comprises one or more nucleic acid bases; and (iii) Z comprises one or more modified nucleotides. According to an aspect, Z comprises at least one modified nucleotide selected from the group consisting of locked nucleic acid, cLNA, bridged nucleic acid, zip nucleic acid, minor groove binder, peptide nucleic acid, and combinations thereof. According to another aspect, Z comprises two consecutive locked nucleic acids at the 3′-terminus of the modified primer.
According to a fourth aspect is the above method, wherein the modified primer comprises the oligonucleotide sequence 5′-YZYZ-3′, wherein: (i) Y comprises one or more nucleotides; and (ii) Z comprises one or more modified nucleotides.
According to a fifth aspect is the above method, wherein the target DNA sequence and at least some of the non-target DNA sequence in the sample differ by only one nucleic acid.
According to a sixth aspect is the above method, wherein the step of detecting the first amplified product comprises the steps of: (i) providing a microarray comprising a set of features including the target DNA probe component for detecting the target DNA sequence, and further including a component intended to serve as a positive control and a component intended to serve as a negative control; (ii) contacting the microarray with the cycled reaction mixture to enable the first amplified product to bind to the target DNA probe component, wherein such binding results in the feature emitting the detectable signal; and (iii) detecting the emitted detectable signal.
According to another aspect, a method for selectively amplifying a target DNA sequence in the presence of non-target DNA sequence in a sample, wherein the target DNA sequence and at least some of the non-target DNA sequence in the sample differ by only one nucleic acid, the method comprising: (i) contacting an oligonucleotide system with the sample under hybridization conditions to form a reaction mixture, the oligonucleotide system including a forward primer and a reverse primer, wherein one of the forward or reverse primer is modified to preferentially increase hybridization between the primer and the target sequence, the modification comprising: (i) a modified 3′ terminal nucleotide, and (ii) one or more additional modified nucleotides; (ii) cycling the oligonucleotide system so that, if the target DNA sequence is present in the sample, the forward primer and the reverse primer hybridize to the target DNA sequence and the reaction mixture results in a first amplified product; (iii) providing a microarray comprising a set of features including at least a target DNA probe component for detecting the target DNA sequence, and further including a component intended to serve as a positive control and a component intended to serve as a negative control, wherein the target DNA probe component comprises a first modification, wherein the first modification preferentially increase hybridization between the target DNA probe component and the first amplified product; (iv) contacting the microarray with the cycled reaction mixture to enable the first amplified product to bind to the target DNA probe component, wherein such binding results in the feature emitting the detectable signal; and (v) detecting the emitted detectable signal; (vi) wherein the target DNA probe component comprises a first modification, wherein the first modification preferentially increases hybridization between the target DNA probe component and the first amplified product.
According to another aspect, a system for selectively amplifying a target DNA sequence, the system comprising: (i) a sample comprising a non-target DNA sequence and potentially comprising the target DNA sequence; (ii) an oligonucleotide system comprising a forward primer and a reverse primer under hybridization conditions to form a reaction mixture, wherein one of the forward or reverse primer is modified to preferentially increase hybridization between the primer and the target sequence, the modification comprising a modified 3′ terminal nucleotide; (ii) a thermocycler adapted to cycle the oligonucleotide system so that, if the target DNA sequence is present in the sample, the forward primer and the reverse primer hybridize to the target DNA sequence and the reaction mixture results in a first amplified product; (iii) a target DNA probe component for detecting the target DNA sequence, the target DNA probe component comprising a first modification, wherein the first modification preferentially increases hybridization between the target DNA probe component and the first amplified product; and (iv) a detector adapted to detect the first amplified product.
According to another aspect, modified 3′ terminal nucleotide is selected from the group consisting of locked nucleic acid, cLNA, bridged nucleic acid, zip nucleic acid, minor groove binder, peptide nucleic acid, and combinations thereof.
According to another aspect, the modified primer further comprises one or more additional modified nucleotides.
According to another aspect, the modified primer comprises the oligonucleotide sequence 5′-XYZ-3′, wherein: X comprises one or more biotin groups; Y comprises one or more nucleotides; and Z comprises one or more modified nucleotides. According to one aspect, Z comprises two consecutive locked nucleic acids at the 3′-terminus.
According to another aspect, the target DNA sequence and at least some of the non-target DNA sequence in said sample differ by only one nucleic acid.
According to another aspect, the detector is a microarray.
According to another aspect, the microarray comprises a target DNA probe component for detecting the target DNA sequence, a component intended to serve as a positive control, and a component intended to serve as a negative control.
According to another aspect, the modified primer comprises the oligonucleotide sequence 5′-YZYZ-3′, wherein: Y comprises one or more nucleotides; and Z comprises one or more modified nucleotides.
According to another aspect, the target DNA probe component comprises at least one modified nucleotide selected from the group consisting of locked nucleic acid, cLNA, bridged nucleic acid, zip nucleic acid, minor groove binder, peptide nucleic acid, and combinations thereof.
The present specification will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
According to one aspect of the invention is a method and system to selectively amplify only a specific allele of a particular gene. For example, described herein are methods and systems that use, in part, a ‘nucleic acid substitute’ to selectively amplify and/or to selectively detect specific alleles such as mutant alleles.
According to one embodiment, the ‘nucleic acid substitute’ can be any of a wide variety of substitutes, including but not limited to Locked Nucleic Acids (“LNA”), cLNA's, Bridged Nucleic Acids (“BNA”), Zip Nucleic Acids (“ZNA”), Minor Groove Binders (“MGB”), Peptide Nucleic Acids (“PNA”), incorporated into amplification primers or Allele Specific PCR (“asPCR”), Mutant Allele Specific Amplification (“MASA”), and/or DNA Duplex stabilizing chemistry, among others.
According to one embodiment of the system or method, the primers used to amplify the genetic sequence are designed such that they only anneal to particular genetic sequences of specific alleles, thus only amplifying those particular alleles. As just one example of the system or method, one would design a primer (or multiple primers, or a primer for each mutation of interest) that does not amplify the wild-type gene (or that selects against any particular known allele of a gene), but that does amplify a particular allele of the same gene. The resulting amplicons generated from the selective amplification may then be applied to a microarray that incorporates probes for particular alleles of the gene. In one embodiment, the probes also use a ‘nucleic acid substitute’ such as LNA's, cLNA's, BNA's, ZNA's, MGB's, and/or PNA's to increase fidelity and improve hybridizing specificity, including probes for the wild-type allele or any allele selected against by primer design. The microarray is then analyzed for which probes hybridized with which amplicons. In the case where an amplicon hybridizes with a wild-type probe or the probe for the allele selected against, the primer either failed or was not properly constructed to select against the amplification of the wild-type allele or any other allele selected against. In a preferred embodiment, little to no amplicon would hybridize with the wild-type probe (or the probe for the allele selected against), thus indicating successful selectivity of the primer. In the case where there is very little or no amplicon hybrized with the wild-type probe (or any other allele selected against), the remaining probes with sequences that are complimentary to particular mutations of the wild-type gene are analyzed. If there are positive hybridizations then the initial cells in the sample included some cells in which genetic or somatic mutations occurred. Information about a particular mutation(s) within a population of cells can be useful for, for example, research concerning particular diseases and their progression. In the clinical setting, the information may inform a clinician about a course of treatment for a particular disease of disease state.
According to another embodiment, the method or system is useful in the case where only a small amount of genetic material in a particular sample contains a mutation. For example, when a tumor is biopsied the resulting tissue may only contain a small percentage of cells that contain a particular mutation in their genetic makeup while the vast remainder of the population is still wild-type or the original germ line sequence. The methods and systems described herein can be used to selectively prevent amplification of the background wild-type or original germ line sequence allele and thereby its later analysis, thereby increasing the signal from the mutations that may be present in the original sample. Identifying mutations at an early stage, for example when they represent only a small fraction of the cells in a tumor, can provide researchers with valuable information concerning particular diseases and their progression and clinicians with more and often more effective options for the treatment of a disease.
Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in
KRAS, also known as “GTPase KRas” or “V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog,” is a protein in humans encoded by the KRAS gene. KRAS is a proto-oncogene (a normal gene that can become an oncogene due to mutation(s), increased expression, or other activation) in which a single amino acid substitution—resulting from a single nucleotide substitution—is responsible for activating the oncogene activity of KRAS. KRAS has been implicated in various types of cancer, including but not limited to lung adenocarcinoma, mucinous adenoma, ductal carcinoma of the pancreas, and colorectal carcinoma, among others. Indeed, mutations in the KRAS gene are estimated to occur in over 90% of pancreatic cancers. Mutations are typically found to affect codons 12, 13, and 61 of KRAS protein, which prevent GTP-GDP exchange, keeping KRAS in the constitutively active GTP bound state. Further, activating mutations in the KRAS gene are associated with poor response to anti-epidermal growth factor receptor (“EGFR”) response. Accordingly, testing for these activation mutations can be an important aspect of anti-EGFR therapy. The presence of a KRAS mutation in a population of cells (such as a tumor) is currently performed through various methods, including real-time PCR and monoclonal antibody tests.
Other oncogenes and proto-oncogenes that could be analyzed include, but are not limited to, NFKB2, NRAS, BCL2, BCL3, BCL6, BRAF, PIM1, IRF4, JUN, LCK, RAF1, MAFB, DDB2, DEK, SMO, ROS1, TET2, NTRK1, FGFR2, EGFR, ERBB2, and MYB, among many others. Further, many other types of genes, alleles, or other locations throughout an organism's DNA complement can be probed and analyzed using the systems and methods described herein.
The resulting amplicons generated from the traditional amplification method depicted in
The probes, which can be part of a microarray or one of several other detection mechanisms, can be unmodified or natural oligos, or, alternatively, can comprise one or more modifications. According to a preferred embodiment, a probe is designed with one or more modifications, including but not limited to any of the modifications described herein, in order to increase the Tm difference and thus increase selectivity. The modification(s) may be anywhere along the probe.
Although this and other examples herein use biotinylated primers, the primers may be absent biotinylation, or may be otherwise modified. For example, one of skill in the art would recognize that there are numerous other types of modification, including but not limited to fluorescence, isotopic labeling, antibodies, and quantum dots, among many others.
As depicted in
where “/5Biosg/” represents a biotin, the “+[A, C, or T]” represents an LNA, and underlining indicates homology with the microarray probe. The Tm depicted in
In another embodiment, as depicted in
where “/5Biosg/” represents a biotin, the “+[A, C, or T]” represents an LNA, and underlining indicates homology with the microarray probe. These primers/probes differ from those depicted in
Although this example depicts two terminal LNAs, the “+[A, C, or T]” could be any other modification described herein or known to one of skill in the art. Further, the one or more modification(s) in addition to the modified nucleotide at the 3′ terminal end could be anywhere along the primer. For example, a primer sequence for 35G>A detection could be any of the following:
Further, there can be multiple modifications in order to further maximize selectivity. For example, a primer sequence for 35G>A detection could be any of the following, among many other variations:
The design of the primer will depend at least in part on the requirements of the system—including but not limited to the target DNA sequence—necessary to sufficiently alter the Tm difference and thereby increase selectivity.
As described above, the primers used for amplification of the KRAS allele in this example are modified by biotin and one or more Locked Nucleic Acids (“LNA”). An LNA is a modified nucleotide with an extra bridge connecting the 2′ oxygen and 4′ carbon. That bridge effectively “locks” the ribose in the 3′-endo conformation, thereby increasing the melting temperature of an oligonucleotide (compare, for example, the “LNA Tm” and “Non-LNA Tm” columns in
Although the primers used for amplification of the KRAS allele in this example are modified by biotin and one or more LNA, the primers and/or probes can be modified in a variety of other ways in order to increase hybridization. This includes, but is not limited to, the incorporation into the primer and/or probe of one or multiple LNAs, cLNA's, BNAs, ZNAs, MGBs, and/or PNAs, among many others. The beneficial result is that when a sample of cells that contain a somatic mutation are analyzed, only the allele(s) of interest is amplified and therefore subsequent analysis is facilitated since the material being analyzed only contains the allele(s) of interest. In conjunction with modifying primers to selectively amplify particular known alleles of a gene a probe system (such as a microarray, fluorescence, enzymatic systems) may also contain modified probe sequences (using Locked Nucleic Acids (LNA's), cLNA's, Bridged Nucleic Acids (BNA's), Zip Nucleic Acids (ZNA's), Minor Groove Binders (MGB's), Peptide Nucleic Acids (PNA's)) that provide for enhanced selectivity in hybridizing with particular alleles of interest. In general the modification increases the Tm difference between the exact matches and the single base mis-matches. Employing the combination of one or more modified primer(s) to selectively amplify one or more known alleles of a somatically mutated gene sequence and to selectively probe the amplification products to analyze the original sample for the presence of sparse populations of somatically mutated genes provides useful information for clinicians and the research community.
In the assay described in Example 2, KRAS is amplified using a mixture of biotinylated KRAS_LNA PCR primers specific to the site of interest and biotinylated KRAS Rev primers. Capture probes with a wild-type “G” at the individual targeted positions are made using the coding strand sequence and will hybridize with the amplified biotinylated non-coding strand. Capture probes that will recognize mutant A, C, or T at the targeted positions are made using the non-coding strand sequence (therefore, T, G, or A at the respective sites) and will hybridize with the amplified biotinylated coding strand. According to one embodiment, the biotinylated LNA modified mutant primers and LNA modified capture probes are made to opposite strands. According to one embodiment, the biotinylated wild-type (generic primer) can be made off of the same strand as the mutant capture probes, and wild-type capture probe made off of same strand as the mutant primers.
As depicted in
where “/5Biosg/” represents a biotin, the “+[A, C, or T]” represents an LNA, and underlining indicates homology with the microarray probe. The Tm depicted in
In another embodiment, as depicted in
where “/5Biosg/” represents a biotin, the “+[A, C, or T]” represents an LNA, and underlining indicates homology with the microarray probe. These primers/probes differ from those depicted in
As described above, the primers used for amplification of the KRAS allele in this example are modified by biotin and one or more LNAs, thereby increasing the melting temperature of an oligonucleotide (compare, for example, the “LNA Tm” and “Non-LNA Tm” columns in
Although the primers used for amplification of the KRAS allele in this example are modified by biotin and one or more LNA, the primers and/or probes can be modified in a variety of other ways in order to increase hybridization. This includes, but is not limited to, the incorporation into the primer and/or probe of one or multiple LNAs, cLNA's, BNAs, ZNAs, MGBs, and/or PNAs, among many others. The beneficial result is that when a sample of cells that contain a somatic mutation are analyzed, only the allele(s) of interest is amplified and therefore subsequent analysis is facilitated since the material being analyzed only contains the allele(s) of interest.
The BRAF gene, also known as “proto-oncogene B-Raf” and “v-Raf murine sarcoma viral oncogene homolog B1,” is a human gene that produces a protein called B-Raf. The B-Raf protein is involved in sending signals inside cells, which are involved in directing cell growth. BRAF is an oncogene, meaning that mutations in the BRAF gene can result or be otherwise involved in cancers such as non-Hodgkin lymphoma, colorectal cancer, malignant melanoma, papillary thyroid carcinoma, non-small-cell lung carcinoma, and/or adenocarcinoma of the lung, among others. To date, more than 30 different mutations of the BRAF gene associated with human cancers have been identified. The diagnosis of a mutation in the BRAF gene can be clinically important, since there are therapies available that target mutations in the gene.
In the assay described in this Example, BRAF is amplified using a mixture of reverse biotinylated BRAF_LNA primers specific to the site of interest, and biotinylated BRAF For primers, as shown in
As depicted in
where “5/Biosg/” represents a biotin, the “+[T]” represents an LNA and underlining indicates homology with the microarray probe. In this case the selective amplification primer is made using the non-coding strand sequence and the selective probe is made using the coding sequence.
As depicted in
where “/5Biosg/” represents a biotin, the “+[A, C, or T]” represents an LNA, and underlining indicates homology with the microarray probe. The Tm depicted in
As described above, the primers used for amplification of the KRAS and BRAF alleles in this example are modified by biotin and/or one or more LNAs, thereby increasing the melting temperature of an oligonucleotide (compare, for example, the “LNA Tm” and “Non-LNA Tm” columns in
The results in
Amplification and Analysis with Chemistry and Reagent Device
The methods and systems described herein can be conducted using a series of physically separated or different analytical or experimental devices, including: a first device or area for preparation of the sample (such as isolation and lysis of the cells) and/or purification of the nucleic acid; a second device for the PCR reaction; a third device comprising a microarray; a fourth device for detection of the microarray signal; and one or more computing devices for capturing, processing, analyzing, visualizing, or otherwise using data obtained from one or more of the analytical or experimental devices. In another embodiment where microarray analysis is replaced by another method of analysis, these experimental and/or detection devices will replace the microarray device listed above.
According to an aspect of the invention, the method is conducted in and/or on a single device capable of sample preparation, PCR, and detection of hybridization. In various embodiments, the device can include: a sample preparation component capable of receiving a biological sample and preparing the sample for PCR; a PCR component capable of receiving the sample from the sample preparation component and performing PCR on a nucleic acid target from the sample in order to produce the PCR results; a microarray component capable of receiving the target amplicon and detecting a hybridization event of the target amplicon to a probe bound to a surface of the microarray; and a support comprising the sample preparation component, the PCR component, and the microarray component.
According to an aspect of the invention, the method is conducted in an integrated microfluidic device known in the art, such as that disclosed in PCT Publication No. WO 2009/049268 A1 entitled “Integrated Microfluidic Device and Methods” by Peng Zhou et al., which is incorporated herein by reference. The method for detecting a nucleic acid target of interest in a sample disclosed herein can be readily adapted for use with an integrated microfluidic device, referred to as an assay unit or, commercially, as a CARD® (Chemistry and Reagent Device)), using methods known in the art, such as the methods disclosed in WO 2009/049268 A1.
“Microfluidics” generally refers to systems, devices, and methods for processing small volumes of fluids. Microfluidic systems can integrate a wide variety of operations for manipulating fluids. Such fluids may include chemical or biological samples. These systems also have many application areas, such as biological assays (for, e.g., medical diagnoses, drug discovery and drug delivery), biochemical sensors, or life science research in general as well as environmental analysis, industrial process monitoring and food safety testing. One type of microfluidic device is a microfluidic chip. Microfluidic chips may include micro-scale features (or “microfeatures”), such as channels, valves, pumps, reactors and/or reservoirs for storing fluids, for routing fluids to and from various locations on the chip, and/or for reacting reagents.
According to an aspect of the invention, the method is conducted in a self-contained, fully automated microfluidic device and system as disclosed in U.S. patent application Ser. No. 13/033,165 entitled “Self-Contained Biological Assay Apparatus, Methods, and Applications,” the entire contents of which are hereby incorporated herein by reference. The device comprises a self-contained, fully automated, biological assay-performing apparatus including a housing; a dispensing platform including a controllably-movable reagent dispensing system, disposed in the housing; a reagent supply component disposed in the housing; a pneumatic manifold removably disposed in the housing in a space shared by the dispensing platform, removably coupled to a fluidic transport layer and a plurality of reservoirs, wherein the fluidic transport layer, the reservoirs, and a test sample to be introduced therein are disposed in the housing in the space separate from the dispensing platform; a pneumatic supply system removably coupled to the pneumatic manifold in the housing in a space separate from the dispensing platform; and a control system coupled to at least one of the dispensing platform and the pneumatic supply system, disposed in the housing. The CARD dispensing platform can further include a motion control system operatively coupled to the reagent dispensing system, wherein the reagent dispensing system includes a reagent dispenser component having a distal dispensing end; and a camera connected to the reagent dispensing system having a field of view that includes at least a selected region of interest of the reservoirs.
According to another non-limiting aspect is an automated process for isolating, amplifying, and analyzing a target nucleic acid sequence using the CARD system. The process includes the steps of providing a pneumatic manifold that operates a microfluidic system having a fluidic transport layer and a fluidic channel disposed therein, and reservoirs attached thereto; introducing the fluid test sample into the fluidic channel; providing at least one reagent to the channel from at least one respective reservoir that is in fluid connection with the fluidic transport layer; combining the fluid test sample and the at least one reagent in a region of the fluidic transport layer, reservoir or amplification reactor; transporting the fluid test sample to a temperature-controlled amplification/reaction reactor that is in operative communication with the fluidic transport layer; incubating the fluid test sample in the amplification/reaction reactor under conditions sufficient to permit the target nucleic acid sequence to be amplified; transporting the fluid test sample to an analysis reservoir; and analyzing the amplified target nucleic acid sequence from the test sample, wherein the test sample is transported from a starting location in the fluidic transport layer to the analysis reservoir separately from any other samples and separately from the pneumatic manifold and the dispensing system.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening.
The recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.
All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed.
No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/561,063, filed on Nov. 17, 2011 and entitled “Selective Molecular Analysis System,” the entire disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61561063 | Nov 2011 | US |
