Shop All RNA Purification Kits

RiboMinus™ Human/Mouse Transcriptome Isolation Kit (Invitrogen™)

The RiboMinus™ Human/Mouse Transcriptome Isolation Kit constitutes a novel purification system that enriches the whole spectrum of mRNA species by depleting large ribosomal RNA molecules in a total RNA sample. The kit removes >95% of 18S and 28S rRNA molecules from human or mouse total RNA (Figure 1) without relying on current polyA+ purification methods. This increases the representation of mRNA species, including non-polyA-tailed, fragmented mRNA or other regulatory RNAs that cannot be purified via polyA-selection methods. Purified RNA is suitable for several downstream applications, including, library construction, RT-PCR, and microarray (Figure 2).

Arcturus™ Paradise™ Plus RNA Extraction and Isolation Kit (Applied Biosystems™)

The ARCTURUS® Paradise® PLUS FFPE RNA Isolation Kit permits unprecedented gene expression analysis of millions of previously inaccessible samples by unlocking RNA from formalin-fixed, paraffin-embedded (FFPE) tissues. Amplify as little as 5 ng of the isolated fixed RNA using reagents and methods that have been specially optimized to overcome the challenges of cross-linked FFPE templates (Figure 1).

Secure Downstream Success with the Paradise® QC Kit
Not all FFPE samples contain high quality RNA. Identify the best samples for your studies using a simple, real-time PCR research technique, and then proceed with confidence using these pre-qualified samples (Figure 2).

Integrated Systems for Microgenomics
The Paradise® PLUS Reagent System is validated as part of the ARCTURUS® complete System for Microgenomics®, an integrated solution for utilizing small quantities of RNA for gene expression analysis, and features the ARCTURUSXT™ Laser Capture Microdissection (LCM) Instrument to procure pure cell populations. ARCTURUS®' Systems for Microgenomics enable accurate and sensitive microarray assays that reveal molecular otherwise obscured in whole tissue samples or cell mixtures.

For Research Use Only. Not for use in diagnostics procedures.

RiboMinus™ Transcriptome Isolation Kit, human/mouse (Invitrogen™)

RiboMinus™ Transcriptome Isolation Kits are novel purification systems that enrich the whole spectrum of RNA transcripts by depleting large ribosomal RNA molecules in a total RNA sample. These kits use a 5µ biotin-labeled, Locked Nucleic Acid (LNA) probe specific for large rRNA to remove 95-98% of rRNA molecules from human, mouse, bacteria, or yeast total RNA (Figure 1). This removal increases the representation of RNA transcript species, including non-poly(A) tailed, pre-processed RNA, small tRNAs, siRNA, snRNA, microRNA, fragmented mRNA, and other regulatory RNAs that cannot be purified via poly(A) selection methods.

The RiboMinus™ Transcriptome Isolation Kits enable:

Comprehensive analysis of the whole transcriptome without contamination or interference from rRNA
• More complete collection of transcribed elements of the genome—no reliance on poly(A) purification methods
• Cleaner, clearer microarray analysis due to higher signal-to-background ratios (Figure 2)

Purified RNA is concentrated and suitable for numerous downstream applications, including microarray analysis (Figure 2), library construction, and qRT-PCR.

GeneJET Plant RNA Purification Kit (Thermo Scientific™)

Thermo Scientific GeneJET Plant RNA Purification Mini Kit is designed for rapid and efficient purification of high quality total RNA from wide variety of plant species and tissue types.

The kit utilizes silica-based membrane technology in the form of a convenient spin column, eliminating the need for expensive resins, toxic phenol-chloroform extractions, or time-consuming alcohol precipitation. The standard procedure takes less than 20 minutes following cell lysis. Purified high quality RNA can be used in a wide range of downstream applications, such as RT-PCR, RT-qPCR, Northern blotting and other RNA-based analysis. RNA yields vary between different species, tissues, and age of tissue sample. See Table 1 for typical total RNA yields from various sources.

Highlights

Fast—procedure completed in 20 min following cell lysis
Convinient—protocol does not include clogging-prone lysate filtration step
High yield—up to 65 µg of high purity and high integrity RNA from 50 mg plant sample
Compatible with wide variety of samples (leaves, roots, sprouts and other parts of various plants)

Applications

• Fast extraction of high purity RNA suitable for all conventional molecular biology procedures, including:
• RT-PCR
• RT-qPCR
• Northern blotting
• Nuclease protection assay

RiboMinus™ Transcriptome Isolation Kit, yeast (Invitrogen™)

RiboMinus™ Transcriptome Isolation Kits are novel purification systems that enrich the whole spectrum of RNA transcripts by depleting large ribosomal RNA molecules in a total RNA sample. These kits use a 5µ biotin-labeled, Locked Nucleic Acid (LNA) probe specific for large rRNA to remove 95-98% of rRNA molecules from human, mouse, bacteria, or yeast total RNA (Figure 1). This removal increases the representation of RNA transcript species, including non-poly(A) tailed, pre-processed RNA, small tRNAs, siRNA, snRNA, microRNA, fragmented mRNA, and other regulatory RNAs that cannot be purified via poly(A) selection methods. The RiboMinus™ Transcriptome Isolation Kits enable:

• Comprehensive analysis of the whole transcriptome without contamination or interference from rRNA
• More complete collection of transcribed elements of the genome—no reliance on poly(A) purification methods

• Cleaner, clearer microarray analysis due to higher signal-to-background ratios (Figure 2)

Purified RNA is concentrated and suitable for numerous downstream applications, including microarray analysis (Figure 2), library construction, and qRT-PCR.

mRNA Catcher™ PLUS Purification Kit (Invitrogen™)

The mRNA Catcher™ PLUS Kit enables high-throughput purification of mRNA from cells, tissues, blood, and total RNA in a 96-well format. By taking advantage of Locked Nucleic Acid (LNA) technology, the mRNA Catcher™ PLUS Kit provides improved performance and a faster protocol, while preserving mRNA yield and purity (see table). The mRNA Catcher™ PLUS Kit offers:

Robust performance—high binding capacity per well (>80 ng/well)
Reproducible results—low CVs from well-to-well and plate-to-plate (~2%)
Optimized protocols—for small sample sizes (100 cells, 4 mg tissue, and 40 µL blood)
Compatible plate design—may be used with most PCR cyclers

How it works
mRNA from total RNA, cells, tissue, and blood samples is hybridized to an immobilized, single-stranded 20-mer oligo(dT)-containing LNA. The incorporation of LNA into the oligo probe increases the hybridization efficiency and specificity of the mRNA binding. The mRNA can either be eluted or directly reversed-transcribed to cDNA directly in the well. The mRNA Catcher™ PLUS method does not require centrifugation, precipitation, phase separation, or column filtration. In addition, the entire method is amenable to automation for streamlined, high-throughput expression profiling for large-scale processes. Isolated mRNA is suitable for use in downstream applications such as RT-PCR and qRT-PCR.

MagMAX™-96 Blood RNA Isolation Kit (Invitrogen™)

This Ambion® kit is for the rapid, high-throughput purification of pathogen RNA from mammalian whole blood, milk, and other biofluids in 96-well plates. RNA purified using the kit is ideal for RT-PCR applications. The kit uses magnetic bead–based purification and includes sufficient reagents for 96 reactions.

• Easily isolate viral or total RNA from whole blood
• Save precious time—complete the protocol in less than 1 hour
• Walk away—integrate with established robotic platforms
• Validated with human, bovine, porcine, and ovine whole blood

Benefits of MagMAX™ Magnetic Bead-Based Purification:
Magnetic beads offer many benefits compared to other technologies for isolating RNA. Beads bind RNA more efficiently than glass fiber filters, resulting in higher and more consistent RNA yields. Additionally, because filters are not used, there is no risk of filter clogging due to cellular particulates in samples. Since only a small volume of magnetic beads is needed for high- efficiency binding, the bound RNA can be eluted in just 30–50 µL of nuclease-free water, concentrating RNA from large, dilute samples.

Isolate RNA from as Little as 50 µl of Blood:
For the highest-quality RNA, use whole blood samples that have not been frozen. Approximately 300–500 ng of intact RNA can be consistently purified from 50 µl of human whole blood. Bovine, porcine, and ovine whole blood samples can also be used. Yields vary from species to species (see data). The recovered RNA is devoid of PCR inhibitors such as proteins and heme, commonly found in RNA isolated from blood.

Isolate Viral and Total RNA from Whole Blood Samples:
The MagMAX™-96 Blood RNA Isolation Kit eliminates sample preprocessing, which can cause sample mix-up and cross-contamination. The procedure is fast (<1 hour), simple, and well suited for automation. The kit can also be used to process fewer than 96 samples at one time and is compatible with either manual processing using multi-channel pipettors or processing with robotic liquid handlers. Downloadable protocols for the use of this kit with specific liquid handling systems are available at our Automation Resource. The MagMAX™-96 Blood RNA Isolation Kit can also be used for total nucleic acid isolation by omitting the DNase treatment.

Accessory Products:
Lysis/Binding Solution Concentrate (SKU#AM8500), Wash Solution 1 Concentrate (SKU#AM8504), and Wash Solution 2 Concentrate (SKU#AM8640) are components of the kit that may also be purchased separately. A 96-well magnetic ring stand is required to use this kit. The Magnetic Stand-96 (SKU#AM10027) and the 96-well Magnetic Ring Stand (SKU#AM10050) are designed for paramagnetic bead precipitation from standard 96-well U-bottom microplates. The Magnetic-Ring Stand pellets the magnetic beads in a circle shape, enabling easy removal of supernatant by a robot or multichannel pipettors. For additional processing plates, Matrix 96-Well U Bottom Polypropylene Plates (Thermo Scientific, Item# 4917) are recommended.

RNAqueous™-96 Automated Kit (Invitrogen™)

The Ambion® RNAqueous®-96 Automated Kit is used for automated, phenol-free total RNA isolation from 100-500,000 cells or 0.1–1 mg tissue using a guanidinium-based lysis/denaturant and glass fiber filter separation technology. The kit contains enough reagents for 384 (4 x 96) RNA purifications. The RNAqueous®-96 Automated Kit uses an RNA-binding glass-fiber filter to provide high, reproducible yields of intact RNA. An optional on-the-filter DNase treatment can be performed to ensure removal of genomic DNA for RT-PCR applications. Downloadable protocols for the use of this kit with specific liquid handling systems are available at our Automation Resource.

Dynabeads™ mRNA DIRECT™ Purification Kit (Invitrogen™)

The Dynabeads® mRNA DIRECT™ Kit is designed for simple and rapid isolation of pure, intact polyadenylated (polyA) mRNA directly from the crude lysate of animal and plant cells and tissues. The isolated mRNA is suitable for use in all downstream applications. Advantages of the Dynabeads® mRNA DIRECT™ Kit:

Fast—15 minute procedure yields pure, intact mRNA
Highly pure mRNA isolation—best choice upstream of cDNA synthesis
Sensitive mRNA isolation—enables cDNA synthesis and cDNA library construction from ultra-small starting samples (enables cDNA library construction from a single cell)

System overview
The isolation protocol relies on base pairing between the polyA residues at the 3' end of most mRNA, and the oligo (dT)25 residues covalently coupled to the surface of the Dynabeads® . Other RNA species lacking a polyA tail will not hybridize to the beads and are readily washed away. Ribosomal RNA, DNA, proteins, and small RNA molecules (such as transfer RNA, micro RNA, and small nucleolar RNA) do not bind to the beads and are discarded. RNase inhibiting agents in the Lysis/Binding Buffer together with stringent hybridization and washing conditions ensure the isolation of pure, intact mRNA from crude samples rich in RNase, without the use of strong chaotropic agents. The mRNA purification beads specifically target and capture the mRNA transcriptome from an extremely wide variety of crude starting samples (see protocol). 1 mg of Dynabeads® Oligo (dT)25 beads (200 µL) binds up to 2 µg of mRNA. A typical mammalian cell contains about 10–30 pg of total RNA, from which 1–5% is mRNA.

RiboMinus™ Transcriptome Isolation Kit, bacteria (Invitrogen™)

RiboMinus™ Transcriptome Isolation Kits are novel purification systems that enrich the whole spectrum of RNA transcripts by depleting large ribosomal RNA molecules in a total RNA sample. These kits use a 5µ biotin-labeled, Locked Nucleic Acid (LNA) probe specific for large rRNA to remove 95-98% of rRNA molecules from human, mouse, bacteria, or yeast total RNA (Figure 1). This removal increases the representation of RNA transcript species, including non-poly(A) tailed, pre-processed RNA, small tRNAs, siRNA, snRNA, microRNA, fragmented mRNA, and other regulatory RNAs that cannot be purified via poly(A) selection methods. The RiboMinus™ Transcriptome Isolation Kits enable:

• Comprehensive analysis of the whole transcriptome without contamination or interference from rRNA
• More complete collection of transcribed elements of the genome—no reliance on poly(A) purification methods

• Cleaner, clearer microarray analysis due to higher signal-to-background ratios (Figure 2)

Purified RNA is concentrated and suitable for numerous downstream applications, including microarray analysis (Figure 2), library construction, and qRT-PCR.

MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit, compatible with PAXgene™ Blood RNA Tubes (Invitrogen™)

The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit purifies total RNA (including miRNA) from PAXgene® Blood RNA Tubes using proven magnetic bead-based technology. A TURBO DNase™ step efficiently eliminates contaminating gDNA ensuring the highest purity RNA possible suitable for real-time RT-PCR and microarray analysis.

• Flexible purification format—use microfuge tubes, manual 96-well plates, or open-format automated 96-well plates from the same kit
• Simple magnetic bead workflow—no spin columns
• Total RNA without RNase activity, contaminating gDNA, or RT-PCR inhibitors

Maximize Total RNA Yields From Blood Samples
The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit utilizes proven magnetic bead-based technology to purify maximal yields of total RNA from PAXgene® Blood RNA Tubes. The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit can recover 3-18 µg from a single PAXgene® Blood RNA tube. A TURBO DNase™ step efficiently eliminates contaminating gDNA that can interfere with downstream applications and ensures the highest purity RNA possible.

The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit performs exceptionally well at purifying miRNA with total RNA from PAXgene® Blood RNA Tubes without having to employ a separate miRNA protocol. One protocol does it all.

The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit can also detect miRNA from PAXgene® Blood RNA tubes as shown by TaqMan® gene expression assays. Users are strongly advised to perform appropriate validation studies against their miRNA targets.

Flexible Purification Formats
The MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit can be processed in low-, medium- or high-throughput formats with superior workflow and handling compared to traditional competitive methods.
• For low-throughput users, the MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit can be used in individual 1.5mL microfuge tubes with the bead?RNA-complex remaining in a single processing tube until the final elution step.
• For medium-to-high–throughput users, the MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit can be done in a 96-well processing plate with either a single or multi-channel pipettor to accelerate the purification process.
• For high-throughput users, the MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit is compatible with manual and automated 96-well processing. Simply process multiple batches of tubes in series or in parallel, through the up-front centrifugation process, to the convenient stopping point, until enough samples can be loaded onto a 96-well processing plate for the RNA purification steps. The RNA purification process can be handled on either open-format liquid handlers, in conjunction with a 96-well magnetic stand on the deck, or magnetic bead movers like the MagMAX™ Express-96 Magnetic Particle Processor (deep well version only).

Rapid Processing Time
Processing times will vary based on format selected, but twelve PAXgene® Blood RNA tubes can be processed manually with the MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit in approximately 2 hours.

An Alternative to Full Purification
For users who perform primarily TaqMan®-based real-time RT-PCR experiments, and do not need to archive RNA⁄cDNA, an alternative to the MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit is the Stabilized Blood-to-CT™ Nucleic Acid Preparation Kit for qPCR. This kit makes it possible to perform expression analysis directly from PAXgene® Blood RNA tubes without conventional RNA purification.

One-Stop Shopping
MagMAX™ for Stabilized Blood Tubes RNA Isolation Kit is compatible with our suite of reverse transcription mixes (SuperScript®), PCR master mixes (both TaqMan® and SYBR® based), and other blood workflow products. Simplify the ordering process and reduce freight cost by getting more from one supplier.

Specifications:
• Yield (Range): 3 - 18µg
• Quality (RIN) ): ≥ 8
• Quality (A260⁄280) ): 1.8 – 2.2
• gDNA (w⁄w) ): <1.56%
• Equipment Needed :
     *Refrigerated centrifuge (4°C) with swing bucket rotor capable of 5,000 x g with
     *50 mL conical tube adapters
     *50ml conical tubes
     *For tube format users: Tabletop microcentrifuge or picocentrifuge
• Number of Preps: 96 preparations (blood tubes)

NOTE: Blood tubes and magnetic stands are sold separately.

NOTE: Blood tubes and magnetic stands are sold separately.

For Research Use Only. Not intended for any animal or human therapeutic or diagnostic use.

PAXgene® and PreAnalytiX® are registered trademarks of PreAnalytiX GmbH. No sponsorship, endorsement, or affiliation is implied herein.

PureLink™ Total RNA Blood Kit (Invitrogen™)

PureLink® Total RNA Blood Kit allows purification of high-quality total RNA from 50 - 500 µl fresh, whole mammalian blood, using non-phenol based purification in a simple spin column based protocol.
• RNA purification from whole blood in under an hour
• Yields high-quality RNA devoid of non-nucleated erythrocytes

Simple RNA Purification from Whole Blood
PureLink® Total RNA Blood Kit is designed for purifying from 50 to 500 µl fresh whole blood or approximately 3.5 x 106 leukocytes (white blood cells) in less than 1 hour. The entire protocol can be done in spin tubes and spin columns.

Leukocyte Enrichment for Improved RNA Purification
Whole blood consists of non-nucleated erythrocytes (red blood cells, 4 - 6 million/mm3) and leukocytes, with the latter present in the minority (5000 - 7000/mm3). Purifying total RNA from whole blood without the removal of erythrocytes results in low RNA yields and clogging of purification columns. The distinct feature of the PureLink® Total RNA Blood Kit is that it employs a leukocyte enrichment step. Hypotonic shock is used to selectively lyse erythrocytes while not affecting leukocytes. Non-nucleated erythrocytes are efficiently depleted, thus significantly reducing cell debris that may otherwise interfere with RNA purification and other downstream applications. Consequently, yields of high-quality total RNA are obtained using the PureLink® Total RNA Blood Kit.

Purified RNA is Suitable for Use with a Variety of Downstream Applications and Products:
Northern Blotting Kits & Reagents
Nuclease protection assays
Microarray
• cDNA synthesis
Real-Time PCR (qPCR)

For Research Use Only. Not intended for animal or human diagnostic or therapeutic use.

MagMAX™-96 for Microarrays Total RNA Isolation Kit (Invitrogen™)

The MagMAX™-96 for Microarrays Total RNA Isolation Kit is for the rapid, high-throughput purification of RNA from mammalian cells and tissue in 96-well plates. The kit combines an organic extraction with magnetic bead–based purification yielding extremely high-quality RNA suitable for the most stringent applications, such as microarray analysis. The kit includes sufficient reagents for 96 reactions. Advantages of the MagMAX™-96 for Microarrays Total RNA Isolation Kit:

• Improve gene expression studies with consistent results from experiment to experiment
• Combines TRI Reagent® with a superior magnetic bead–based technology
• Streamlined RNA purification, without sacrificing RNA quality or quantity
• Requires less hands-on time than competitor kits
• Can be integrated with established robotic platforms
• Best MagMAX™ kit for difficult samples or large volumes

Benefits of MagMAX™ magnetic bead–based purification
Magnetic beads offer many benefits compared to other technologies for isolating RNA. Beads bind RNA more efficiently than glass fiber filters, resulting in higher and more consistent RNA yields. Additionally, because filters are not used, there is no risk of filter clogging due to cellular particulates in samples. Since only a small volume of magnetic beads is needed for high- efficiency binding, the bound RNA can be eluted in just 20–50 µL of nuclease-free water, concentrating RNA from large, dilute samples.

Highly stringent for the best-quality RNA
The MagMAX™-96 for Microarrays Total RNA Isolation Kit (patent pending) procedure combines the robust and reliable lysis/denaturant TRI Reagent® with MagMAX™ magnetic bead–based RNA purification technology, resulting in streamlined RNA purification, even in a high-throughput format, without sacrificing RNA quantity or quality. TRI Reagent® readily lyses even difficult cells and tissues while denaturing nucleases to maintain the integrity of RNA. The kit provides high yields of pure, intact RNA that can be used directly for quantitative reverse transcriptase PCR (qRT-PCR) and microarray analysis. See the accompanying data showing RNA yield and quality obtained when using the MagMAX™-96 for Microarrays Total RNA Isolation Kit. Also shown is data illustrating a high correlation between the method that Affymetrix recommends for producing RNA for use on their GeneChips® and the method that the MagMAX™-96 for Microarrays kit employs.

Fast, flexible procedure
Two alternative protocols are supplied for the kit. The "Spin" method has fewer steps, requires no DNase treatment, and allows for larger sample amounts to be processed. The "No Spin" method requires less sample handling and can easily be integrated with a robotic liquid handler. The procedure is fast (<1 hr), simple, and well suited for automation. The kit can also be used to process fewer than 96 samples at one time and is compatible with either manual processing using multi-channel pipettors or processing with robotic liquid handlers. Downloadable protocols for the use of this kit with specific liquid handling systems are available at our Automation Resource.

Accessory products
A 96-well magnetic ring stand is required to use this kit. The Magnetic Stand-96 (Cat. No. AM10027) and the 96-well Magnetic Ring Stand (Cat. No. AM10050) are designed for paramagnetic bead precipitation from standard 96-well, U-bottom microplates. The Magnetic-Ring Stand pellets the magnetic beads in a circle shape, enabling easy removal of supernatant by a robot or multichannel pipettors. For additional processing plates, Matrix 96-Well U Bottom Polypropylene Plates (Thermo Scientific, Item# 4917) are recommended.

MEGAclear™ Transcription Clean-Up Kit (Invitrogen™)

The MEGAclear™ Kit is designed for the quick cleanup of any large-scale transcription reaction. The MEGAclear™ Kit efficiently separates RNA from unincorporated NTPs, enzymes, and buffer components. Advantages of the MEGAclear™ Kit:

• Purifies transcription reactions to produce high-quality RNA, free of unincorporated NTPs, enzymes, and buffer components
• High recovery from 1 ng to 500 µg of input
• Ideal for purification of aRNA amplification reactions, nonisotopically labeled RNA probes, and capped RNA transcripts for oocyte injections
• Quick protocol—purify RNA in less than 30 minutes

Using the MEGAclear™ Kit
The protocol is quick and easy. The transcription reaction is mixed with Binding Solution, passed over an RNA-binding filter, and washed; an elution step releases the purified RNA, which is now ready for any application requiring highly pure synthetic or in vitrotranscribed RNA. For RNA recovery of 70% or greater, single-stranded RNA should be >100 nt and double-stranded RNA should be >200 bp.

Mouse RiboPure™-Blood RNA Isolation Kit with Manual (Invitrogen™)

For the purification of extremely high-quality total RNA (and optionally, microRNA) from mouse or rat blood in about 35 minutes. The Ambion® kit includes sufficient reagents for 25 RNA purifications from whole blood samples ranging from 0.1–0.5 each.

• Includes RNAlater®, predispensed in 2 mL tubes, for RNA stabilization
• Resulting RNA is suitable for stringent downstream applications such as array analysis and qRT-PCR

Due to interference from the enzymatic inhibitors and anticoagulants present in blood samples, RNA purification from whole blood requires a stringent isolation method that yields high-quality RNA depleted of inhibiting agents and contaminants. The kit includes microfuge tubes preloaded with RNAlater® Tissue Collection:RNA Stabilization Solution, an aqueous, nontoxic storage reagent that prevents RNA degradation and preserves RNA profiles within samples. Stabilized samples can be stored at room temperature for up to 3 days or at –20°C for long-term storage. The related Figures show the performance of RNA isolated with the Mouse RiboPure™-Blood Kit in real-time RT-PCR. The kit includes an alternative protocol for isolating total RNA that contains microRNA. Typically, 30–55 µg of total RNA (containing microRNA) is obtained from 0.5 mL mouse blood. Yields from rat blood are considerably more variable, generally 18–40 µg from 0.5 mL blood.