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Products - DNA Microarrays - H25K Human Genome


ArrayIt® is pleased to announce H25K, the world’s first human genome microarray based on a completely sequenced human genome and derived from a fully annotated set of 25,509 human genes. This “next generation” microarray represents a significant advance over competing products consisting of collections of expressed sequences tags (ESTs) from poorly annotated sequence databases.  H25K is a multi-purpose microarray containing 26,304 long oligonucleotides designed to maximize studies of the entire human genome in a single biochemical reaction. Users can utilize samples prepared from genomic DNA, mRNA and protein to study problems ranging from karyotyping and gene expression profiling to chromatin structure and protein-DNA interactions. For gene expression users, our revolutionary one spot-one gene™ design allows the quantitative measurement of >300,000 human transcripts in a single hybridization reaction. Users interested in the raw H25K oligonucleotide sequences may purchase one or all of the 26,305 oligonucleotides that comprise H25K. The most advanced bioinformatics, oligonucleotide manufacturing, microarray printing, and surface chemistry provide unprecedented specificity and sensitivity, allowing streamlined data analysis and mining.  Fully compatible with an installed base of >10,000 microarray slide scanners, H25K sets a new standard for human genome microarrays.

Contents

  • Introduction
  • Quality Control
  • Product Description
  • Kit Contents
  • Technical Notes
  • Short Protocols
  • Complete Protocols
  • Technical Assistance
  • Troubleshooting Tips
  • Recommended Equipment
  • Ordering Information
  • Storage Conditions
  • Warranty


Introduction
The use of ArrayIt® brand products will improve the precision, speed and affordability of your microarray research in genomics, proteomics, biomedicine, pharmaceuticals and diagnostics. This handbook contains all the information required to take full advantage of Arrayit's ArrayIt® brand H25K Human Genome Microarrays.

Quality Control
Arrayit uses the highest quality control (QC) and quality assurance (QA) measures to ensure the quality of our ArrayIt® brand H25K Human Genome Microarrays.  The finest science and engineering was used to develop this product.  The use of advanced bioinformatics, ultra-pure oligonucleotides, superior surface chemistry and the world’s most advanced microarray cleanroom manufacturing facilities guarantees that H25K outperforms the highest industry standards.

Product Description
ArrayIt® brand H25K Human Genome Microarrays represents the highest quality human genome microarray in the microarray field. All of our whole human genome chips are designed from a complete and fully annotated human genome sequence using sophisticated one spot-one geneTM informatics. H25K is manufactured in a state-of-the-art class 100 cleanrooms using our patented contact printing technology (U.S. 6,101,946), with the strictest QC and QA procedures.  H25K offers quality and performance that cannot be obtained from any other vendor.

Users will appreciate the following features of H25K

  • Designed from the complete, fully annotated human genome sequence
  • Annotated across GenBank, UniGene, GoldenPath, RefSeq and AceView
  • Contains a total of 26,304 long oligonucleotide elements
  • Novel one spot-one geneTM design streamlines data analysis
  • Explore the function of 25,509 verified human genes
  • Devoid of pseudogenes, and redundant and chimeric sequences
  • A total of 795 control sequences that add precision and reliability
  • Contains widely used Ambion and Stratagene controls
  • Multiple uses including karyotyping, expression analysis, mapping and others
  • Compare human, primate and rodent genomes
  • Detect >300,000 human mRNAs in a single hybridization reaction
  • Purchase one or all of the 26,304 oligonucleotide sequence set
  • Map chromatin domains genome-wide
  • Manufactured using Arrayit’s patented printing technology (U.S. 6,101,946)
  • Oligonucleotides made “off-line” exceed 99% purity levels
  • Content verified using mass spectrometry to ensure integrity
  • Printed on atomically flat glass substrates for improved precision
  • Compatible with an installed base of >10,000 slide scanners
  • Use H25K to validate Affymetrix, Agilent, ABI, GE and other vendors
  • Printed elements occupy a convenient 18 x 54 mm area
  • 50 µl reaction volume accelerates kinetics and minimizes sample consumption
  • Chip contains 48 sub-grids (24 x 24) of 125 µm printed elements
  • Format compatible with all standard data quantification and mining packages
  • Compatible with dozens of DNA and RNA amplification and labeling schemes
  • Utilize fluorescent, colorimetric and chemilluminscent detection
  • One, two, three and four color detection possible
  • Detect limit: 1 mRNA per 1,000,000
  • Dynamic range: >1,000,000-fold
  • Chip-to-chip CVs: ±20%
  • Corner chamfer provides unambiguous spatial orientation
  • Barcode assists in data tracking
  • Sophisticated anti-static packaging improves usability
  • Produced in ArrayIt®’s high volume microarray manufacturing facility
  • Microarrays arrive processed and ready to use
  • Stable for 6 months from the date of purchase
  • Explore the entire human genome in a single experiment!
     

Kit Contents
Each H25K Human Genome Microarray kit contains the following components:

  • 1 x H25K Human Genome Microarray
  • 1 x Human Discover Chip
  • 1 x H25K Lifter cover slip (22 x 60 mm)
  • 1 x Discover Chip cover slip (22 x 22 mm)
  • 1 x H25K Human Genome Annotation (downloadable using the link below)

 

Figure 1. Shown is the H25K Human Genome Microarray kit. Each kit is manufactured and packaged in class 100 cleanrooms and heat-sealed in anti-static packaging to ensure optimal performance for 6 months from the date of purchase.  Kit contents include an H25K Human Genome Microarray, a Human Discover Chip, and cover slips.  Complete H25K gene annotation information is available electronically via the Internet (see below).

Technical Notes
The ArrayIt® H25K Human Genome Microarray contains 26,304 features or “spots” representing 25,509 fully annotated human genes, as well as 795 control sequences from mouse, plant and other sources.  H25K oligonucleotides contain SENSE strand information, and therefore nucleic acid probe mixtures reacted with H25K must contain ANTI-SENSE molecules to hybridize to the SENSE oligonucleotides present on the chip. The long oligonucleotide sequences present in each feature are annotated across the AceView, Entrez, RefSeq, UniGene, KnownID, and GenBank databases. Each oligonucleotide also includes a unique MicroarrayID, which identifies the sequence on H25K and allows customers to purchase the sequence by specifying the MicroarrayID in the catalog number (see Ordering Information). Gene descriptions are based on the best descriptions available from GenBank and AceView.  A complete description of the annotation information is provided in Table 1.

Table 1. Provided are descriptions of the H25K annotation information.

H25K Annotation

Description

MicroarrayID

Microarray specific identifier for H25K. Use the last 5 digits to order H25K oligonucleotide sequences (see Ordering Information)

GeneName

AceView name from the Nov 04 build.  See the website below (http://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/) for more information

S

Some AceView genes have more than one expressed region, and different expressed regions are distinguished using S numbers. The gene name and the S number define a unique expressed region

GeneID

Identifier from Entrez Gene, NCBI

RefSeqID

Identifier from the RefSeq (Reference Sequence) database, NCBI

UniGeneID

Identifier from the UniGene database, NCBI

KnownID

Gene name from Known Gene table, UCSC Genome Browser, May 2004 build

GenBank

Best GenBank record, NCBI

Description

Best description of the gene from GenBank and/or AceView, NCBI

The H25K Human Genome Annotation is intended for current and prospective H25K users only. Please click on the link below to download the complete H25K gene content.

Click here to download the H25K Human Genome Annotation.

The H25K content is printed as 48 sub-grids of 24 x 24 spots spaced at 185 µm centers. The printed H25K microarray occupies an 18 x 54 mm area on the glass substrate, positioned evenly positioned from left to right and top to bottom between the top of the substrate and the barcode. The 12.5 x 19 mm barcode includes the product name, website, barcode, and unique 6 digit tracking number (e.g. 100012) as shown in Figure 2. The barcode information is included to allow unambiguous H25K sample tracking at the customer site. Barcode information is also used at the ArrayIt® manufacturing centers for quality control and quality assurance purposes.  One major advantage of H25K compared to competing human genome microarrays is that our patented contact printing method and glass substrates allow visual inspection of every printed H25K chip, guaranteeing the presence of the printed elements. This contrasts with in situ synthesis approaches, which produce microarrays with “invisible” synthesized elements that are not amenable to direct inspection. The H25K inspection process on a microarray-by-microarray basis provides the customer with a level of QA and QC that is not possible with competing products.


Figure 2. Shown is a photograph of an H25K Human Genome Microarray Barcode.  The barcode label (12.5 x 19 mm) contains the product name, ArrayIt® web address, barcode and numerical identifier.  The barcode label is positioned on the “business side” of H25K at the bottom of the glass substrate.

Short Protocol (Steps 1-7)
1. Prepare a labeled probe from a biological sample.
2. (Optional) Test the labeled probe mixture on a Human Discover Chip.
3. React the probe sample with H25K to allow molecular binding.
4. Wash H25K to remove unbound probe molecules.
5. Detect H25K signals by scanning or imaging.
6. Quantify the H25K signals.
7. Perform data analysis.

Complete Protocol (Steps 1-7)
1. Prepare a labeled probe from a biological sample. H25K contains 26,304 long oligonucleotides representing every gene currently known in the human genome.  These gene-specific hybridization targets can be used to explore the genome, transcriptome and proteome in a variety of applications. Probes can be prepared from human DNA, mRNA and protein samples, or from homologous species such as primates and rodents.  Sample mixtures can be complex and of native origin or from synthetic recombinant sources, such as in cases where H25K is being used to map “contigs” or artificial chromosomes. H25K can be used to query a single probe mixture, or multiple probes prepared using multiple fluorescent labels in multi-color DNA and RNA hybridization. For gene expression applications, each oligonucleotide designed to be complimentary to the 3’ end of a gene and is optimized to hybridize to as many transcripts as possible in cases where genes express multiple mRNAs.  H25K can detect as many as 300,000 human mRNAs in a single reaction.  There are three fundamental principles that should be used for H25K sample preparation: (1) Sample integrity must be high. DNA, mRNA and protein molecules must be full length and free of contaminating enzymes that can produce nucleic acid and protein degradation. (2) Probe labeling must be efficient.  Probes should be checked prior to reactions with H25K to ensure that the probe mixtures are highly fluorescent, or contain the expected epitopes such as amino-allyl or biotin. The most common cause of poor performance with H25K is poor sample/probe preparation. (3) Probe mixtures must be pure. Prior to reactions with H25K, probe mixtures should be purified to remove non-incorporated dyes and other contaminants that can increase background noise.  This step is well worth the small investment in time and money, as it will greatly increase performance. Direct and indirect fluorescent and non-fluorescent labeling techniques have been described extensively in the literature and a host of commercial labeling kits are available from many different vendors. ArrayIt® offers an extensive line of purification, amplification and labeling kits for DNA, mRNA and protein labeling applications. For mRNA purification, amplification and labeling, ArrayIt® offers the Micro-Total RNA Extraction Kit, MiniAmp mRNA Amplification Kit, Indirect Amino Allyl Fluorescent Labeling Kit, and Universal Reference mRNA.  Through various amplification strategies, it is possible to examine DNA and RNA derived from as few as 10 human cells. Prior to probe preparation, samples of genomic DNA can be treated with nucleases to map chromatin-binding regions.

2. (Optional) Test the labeled probe on a Human Discover Chip. Each H25K Human Genome Microarray Kit includes a Human Discover Chip, which is a test microarray containing long oligonucleotides complementary to 380 human genes. To open the H25K Kit, cut the silver anti-static bag between the heat seal and the zip-lock approximately 1.0 cm below the top end of the package using a scissors. This will allow the silver package to be re-sealed if only a portion of the H25K Microarrays is used. The silver package contains a white box with H25K and the Discover Chip, and a thin plastic cassette that houses the cover slips. To open the white H25K box, lift the top gently upward while holding the bottom firmly in the other hand.  Once the box is opened, remove the white cleanroom cloth by lifting it gently upward.  Avoid dragging the cleanroom cloth across the glass substrates as this may cause fraying of the cloth.  The Human Discover Chip contains a 9 x 9 mm microarray located on the upper third of the glass substrate. A portion of a probe mixture destined for H25K can be tested on the Human Discover Chip in advance of using the more expensive H25K product. Probes mixtures prepared from DNA, RNA and protein (5-10 µl) can be applied to the Human Discover Chip using the 22 x 22 mm included in the H25K Kit. Make sure to open the thin plastic cassette carefully as the cover slips are fragile and can be broken if mishandled. Use H25K steps 3-7 below as a guide for the Human Discover Chip test experiment. The Discover Chip annotation can be downloaded from the Human Discover Chip website. Step 2 is optional, and users with a high confidence in their technique and probe quality may omit this step and proceed directly to using H25K.

3. React the probe sample with H25K to allow molecular binding.  The 26,304 printed elements of H25K are located in an 18 x 54 mm area on the barcode side of the glass substrate. For additional help with side orientation, the 1.4 mm cropped corner of the glass substrate (“chamfer”) should be located in the upper right corner of the glass substrate when the barcode is facing upward. The Figure 3 photograph shows the side of the glass substrate that contains the H25K microarray. Do not attempt to react probe mixtures with the backside of H25K, as negative results will be obtained.  Gloves should be worn at all time while handling H25K to avoid the transfer of dust, debris, hand oils, and other contaminants that can interfere with H25K use. ArrayIt® Microarray Cleanroom Gloves provide superior hand protection for microarray applications. The minimum probe sample volume for H25K is approximately 50 µl. A 50 µl probe sample forms a 40 µm layer when using the 22 x 60 mm lifter cover slip included in the H25K Kit.  ArrayIt® provides an affordable and widely used line of Hybridization Cassettes for H25K probe sample reactions, and Hybridization Cassettes work very well for low to medium throughput applications.  Users may also employ automated hybridization stations to allow automated reactions and washing of H25K (Fig. 4).  Typical probe sample volumes for hybridization stations are 50-200 µl depending on the instrument, and users should consult the product documentation provided by the vendor to ensure the correct probe volume. Probe mixtures can be generated from cloned or cellular DNA, RNA or protein, and dozens of fluorescent and non-fluorescent labeling schemes have been described in the scientific literature.  Probe mixtures should be reacted for 5 minutes to 6 hours, depending on the probe sample concentration and complexity.  Probes derived from cloned and recombinant sources will probably produce satisfactory results within 5-10 minutes, as the molecular complexity of such sources is low and H25K performance is extremely high.  Probe mixtures derived from complex sources such as human genomic DNA, mRNA and protein may require up to 6 hours to produce strong signals. In rare cases, users may opt for 6-18 hour reaction times, though probe drying and elevated background noise can become an issue with prolonged incubations. After the probe reaction is complete, users should proceed quickly to the wash steps to prevent probe drying and elevated background.

4. Wash H25K to remove unbound probe molecules.  After the probe binding reaction is complete, H25K should be washed to remove unbound material.  In the case of H25K hybridization reactions, oligonucleotide-DNA or oligonucleotide-RNA hybrids are typically washed at high-stringency to remove labeled probe molecules that have bound weakly or non-specifically.  Lesser stringency can be use in cases where DNA and mRNA probe mixtures are derived from homologous species such as primate, mouse and rat. For protein binding applications, oligonucleotide-protein complexes should be washed to remove proteins that have bound weakly or non-specifically.  H25K oligonucleotides are bound in a highly stable manner to the glass substrate, and therefore the oligonucleotides themselves are stable to elevated temperature (=70°C), low salt, and other neutral pH (pH 6-8) treatments. Users should avoid extremes in temperature and pH to avoid damaging the H25K oligonucleotides.  ArrayIt® Wash Buffers A, B and C are extremely good reagents for the wash steps required for DNA, cDNA, mRNA, and aRNA hybridization experiments with H25K. Elevating the wash temperature of Wash Buffer C from 25-65°C provides a convenient and efficient means of controlling H25K hybridization stringency.  Protein experiments with H25K typically make use of a series of room temperature (20-25°C) washes with phosphate-buffered saline (PBS) buffers containing dilute additions of detergent (e.g. 0.1-0.01% TritonX100). Prior to washing, the lifter slip must be removed from the H25K surface to allow efficient washing and to avoid scratching the H25K surface.  After removing the lifter slip, place the H25K Human Genome Microarray into the first wash buffer (e.g. Wash Buffer A) and wash vigorously for 5 minutes.  After 5 minutes in the first wash buffer, transfer H25K to the second wash buffer (e.g. Wash Buffer B) and wash for 5 minutes.  A 5-minute wash in a third wash buffer (e.g. Wash Buffer C) should be sufficient to complete the wash process.  A total of three 5-minute washes should be sufficient to remove unbound probe molecules in any H25K application.  Users can experiment with different wash buffers and different temperatures (20-65°C) to optimize the washing process for a particular H25K application. Both manual and automated washing procedures work well for H25K. The ArrayIt® High Throughput Wash Station works well for manual washing procedures (Fig. 6).

5. Detect H25K signals by scanning or imaging. After the wash steps, wash buffer remaining on the H25K chip should be removed prior to detection. Centrifuge for 5-10 seconds (2,000 x g) in a Microarray High Speed Centrifuge works well for drying H25K. After the centrifugation step, H25K should be inserted into a microarray scanning or imaging device to acquire the signals. The SpotLight Microarray Fluorescence Scanner works well for this application, though H25K is compatible with all major brands of microarray glass slide scanners including systems manufactured by PerkinElmer, Axon, Bio-Rad, Applied Precision, and others. Scanners and imagers should be capable of at least 10 µm resolution, the recommended resolution setting for H25K. The selected scan area should be 22 x 60 mm.  In addition to the resolution and scan area settings, correct settings should be used for wavelength(s), gain, laser intensity, PMT, and other technical parameters required to produce high quality, data-rich images. Applications such as genotyping and mapping typically produce signal intensities spanning only 1-2 orders of magnitude, and in such cases a single set of instrument settings and a single image usually suffice to capture all of the H25K data. For expression analysis applications involving complex mixtures of mRNA varying greatly in concentration, multiple scanner settings (e.g. low and high sensitivity) across two or more images can be used to capture signals spanning up to 6 orders of magnitude.  Multi-color experimentation involving, for example, cyanine 3 and cyanine 5 labels, obviously require data capture at two different wavelengths (e.g. 532 and 635 nm). H25K images should be saved as 16-bit TIFF files for quantification and downstream analysis.  A 10 µm scan of H25K (block 20) hybridized with a Cy3-labeled test probe is shown in Figure 7. Click on the link in the Figure 7 legend to download the H25K block 20 content map and partial annotation.

6. Quantify the H25K signals.

7. Perform data analysis.


Figure 3. Shown is the H25K Human Genome Microarray orientation and location.  The printed H25K microarray occupies an 18 x 54 mm area (red) on the same side of the glass substrate as the barcode.  Samples reacted with H25K, either by cover slip and through the use of an automated hybridization stations, must exceed the printed area shown to ensure coverage of all 26,304 printed elements.  The 22 x 60 mm lifter slip included in the H25K Kit provides sufficient coverage of the printed area.


Figure 4. Shown is the H25K Human Genome Microarray being used in conjunction an automated hybridization station. The Advalytix SlideBooster 4001 Microarray Hybridization Station (ArrayIt® Cat. HSAW) employs acoustic wave technology to rapidly mix H25K probe mixtures during the reaction step of H25K. The SlideBooster uses 60 µl probe volumes of nucleic acids and proteins beneath the 22 x 60 mm lifter slip to achieve strong signals in =60 min.  Up to four H25K Human Genome Microarrays can be reacted simultaneously with the SlideBooster 4001. Users should follow the manufacturer’s instructions carefully when using this instrument with H25K.


Figure 5. Shown is the ArrayIt® High Throughput Wash Station used for the H25K wash steps. Following the probe reaction step and lifter slip removal, H25K can be washed using an ArrayIt® High Throughput Wash Station (Cat. HTW) filled with 400 ml of the appropriate wash buffer (e.g. Wash Buffer A, B or C).  Buffer agitation is achieved using a stir bar located in the base of the HTW and a magnetic stir plate. The sturdy slide rack holds H25K in place during the washes.


Figure 6. Shown is a scanned image of H25K hybridized with a Cy3-labeled test probe. H25K was hybridized using a 22 x 60 mm lifter slip for 5 min with a Cy3-labeled oligonucleotide test probe, washed to remove unbound probe molecules, and scanned at 10 µm resolution using an GenePix 4000A microarray scanner (Axon Instruments and Molecular Devices) set at PMT gain 750 and 100% laser power in the 532 nm channel. The scan encompasses 544 printed elements (125 µm diameter and 185 µm centers) from H25K block 20 (row 5, column 4), and the space bar represents 500 µm.


Figure 7. Typical hybridization results of the H25K microarray.

Technical Assistance
Please contact us if you have any questions, comments, suggestions, or if you need technical assistance.  By electronic mail, use
Cette adresse email est protĂ©gĂ©e contre les robots des spammeurs, vous devez activer Javascript pour la voir. and type "H25K technical assistance" into the subject line. By telephone, call (408) 744-1331 between the hours of 8AM and 7PM PST Monday through Friday.  We want to hear about your successes and are always happy to publish contributed H25K sample data on our website.

Troubleshooting Tips
1. Weak signals

  • Degraded DNA, RNA or protein.  Check sample integrity.
  • Poor sample labeling efficiency. Check probe mixture.
  • Wash stringency too high.

2. High background fluorescence

  • Probe mixture drying out during hybridization. Keep hydrated for duration.
  • Probe drying after hybridization.  Transfer quickly to wash steps.
  • Probe volume too low.  Use =50.0 µl for H25K.
  • Purify probe mixture to remove contaminating unincorporated fluors.
  • Hybridization time too long. Use a maximum time of 6 hrs.
  • Poor washing procedure.  Increase time or stringency.

3. Low frequency of differentially expressed genes (gene expression)

  • Wash stringency too low. Reduce salt and/or increase temperature.
  • Messenger RNA samples highly similar.  Check samples/stimuli.

4. Artifacts observed in two-color experiments (gene expression)

  • Dye effects to blame.  Swap colors and re-examine data.

Recommended Equipment

  • 946 Pins and Printheads
  • SpotLight Microarray Fluorescence Scanner
  • Hybridization Cassettes
  • Hybridization Buffers
  • Microarray High Speed Centrifuge
  • High Throughput Wash Station
  • Microarray Cleanroom Gloves
  • Microarray Cleanroom Wipes
  • Microarray Air Jet
  • Micro-Total RNA Extraction Kit
  • MiniAmp mRNA Amplification Kit
  • Universal Reference mRNA
  • CheckIt Chips
  • Nanoprint Microarrayers
  • SpotBot® 2 Personal Microarrayers

Ordering Information

Product

Description

Catalog ID

ArrayIt® 25K Human Genome Microarray

ArrayIt®'s new Human Genome Microarray contains 26,304 long oligonucleotides specific for 25,509 fully annotated human genes. Our revolutionary one spot-one gene™ design utilizes the most advanced bioinformatics, contact printing, and surface chemistry to deliver performance specifications of unprecedented specificity and sensitivity, allowing streamlined data analysis and mining. This all-purpose human genome chip enables a host of scientific applications including DNA and RNA homology studies, gene expression monitoring, artificial chromosome mapping, protein binding studies, and others.  Fully compatible with an installed base of >10,000 microarray slide scanners, H25K sets a new standard for human genome microarrays.

H25K

 

Product

Description

Catalog ID

H25K Oligo Sequence

Primary nucleotide sequence of specific long oligonucleotides present in the H25K Human Genome Microarray. Customers can obtain raw sequence information for one or more of the 26,304 oligonucleotides that comprise the H25K product. ArrayIt®’s revolutionary one spot-one gene™ design utilizes the most advanced bioinformatics and the complete human genome sequence to obtain fully optimized H25K oligonucleotides that are highly gene specific.  This convenient program allows users to obtain some or all of the H25K design simply by purchasing the oligonucleotide sequence information. Ideal for users studying specific human gene subsets.  The catalog ID of each oligonucleotide uses a common prefix (H25KS) and then adds the unique 5-digit TCHA numerical identifier for each sequence as a suffix (e.g. 07265) to form the complete catalog ID (e.g. H25KS07265). TCHA identifiers for each oligonucleotide can be found in the H25K Human Genome Annotation file.

H25KS0000 1 to H25KS2630 4 (please refer to the H25K annotation for  TCHA identifiers)

Storage Conditions
Arrayit's H25K Human Genome Microarrays are manufactured and packaged in state-of-the-art class 100 Cleanroom facilities and are stable at room temperature (25°C) for 6 months from the date of receipt. Store in the sealed anti-static shipping envelope and avoid exposure to elevated temperature, humidity, and dust until use.

Warranty
Arrayit's H25K Human Genome Microarray has been scientifically developed and manufactured in a state-of-the-art class 100 Cleanrooms. H25K is sold for research purposes only and is not for use in human diagnostics or for drug purposes, and should not be administered to humans in any way.  Extreme care and exact attention should be practiced in the use of the materials described herein.  All Arrayit products are subject to extensive quality control and are guaranteed to perform as described when used properly.  Any problems with these products should be reported to Arrayit immediately.  Our liability is limited to the replacement of the product, or a full refund.  Any misuse of this product is the full responsibility of the user, and Arrayit makes no warranty or guarantee under such circumstances.