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    Cat. No.
    25 Preps

    *link will take you to our distributor which supports all Academic and Government Institutes. All other customers please submit your order to orders@meridianlifescience.com


    Highly efficient purification of miRNA and total RNA by combining the stringency of guanidinium thiocyanate lysis with the speed and purity of silica-membrane column purification.

    Product Highlights

    • Fast – streamlined protocol for reliable extraction of all miRNA species in as little as 25 minutes from a wide variety of sample types
    • Specific – buffering conditions and column matrix specially developed for extraction of the miRNA population
    • Efficient – excellent recovery of all small RNA species (<200 nt) from even very limiting amounts of sample
    • Unbiased – column-based purification eliminates bias in the small RNA molecule population that can occur with organic solvents
    • Versatile – delivers high-purity miRNA from a variety of sample types including cells, tissue, bacteria and bodily fluids.
    • Convenient - optional protocol for parallel extraction of all larger RNA species thereby enabling extraction of total RNA

    Product Description

    The ISOLATE II miRNA Kit provides a simple, efficient column-based method for the isolation of miRNA and total RNA from a wide variety of starting materials, without the need for hazardous reagents such as phenol, which has been reported to introduce significant bias in recovery of selected small RNAs.

    By combining the stringency of guanidinium-thiocyanate lysis with the speed and ease-of-use of two silica-membrane purification columns, the ISOLATE II miRNA Kit provides a fast method for the purification of high-quality total RNA (on the first column) and miRNA (on the second column) from cultured animal cells, small tissue samples, bacterial cells, plants and blood.

    For applications that are sensitive to very small amounts of DNA, residual amounts of DNA remaining can be removed using a convenient on-column DNase treatment with RNase-free DNase I that is supplied with the kit.

    The ISOLATE II miRNA Kit has been designed to deliver optimal performance in miRNA expression profiling and quantification using qPCR, microarrays, small RNA library construction for small RNA-Seq, as well as single cell assays.


    • RT-qPCR
    • miRNA profiling
    • End-point RT-PCR
    • Array analysis
    • Northern blotting
    • Tissue expression profiling
    • Biomarker discovery
    • Microarray analysis
    • RNA-Seq
    Fast purification of high-quality miRNA and total RNA from cultured cells, tissues and biofluids.

    Nucleic Acid Isolation Guide

    Download the ISOLATE II Guide with detailed product descriptions and performance data to help you choose the best product for your research

    Product Selection

    Please refer to the ISOLATE II Selection Chart to confirm the applications for which ISOLATE II miRNA Kit is the most recommended kit for your application.


    Certification of Analysis (COAs)



    Reagent 25 Preps
    ISOLATE II Large RNA Removal Columns 25
    ISOLATE II miRNA Columns 25
    Collection Tubes (2 mL) 50
    Elution Tubes (1.7 mL) 50
    Lysis Buffer RX 40 mL
    Wash Buffer W1 38 mL
    DNase I Solution (RNase-free) 0.8 mL
    DNase I Reaction Buffer DRB 6 mL
    RNA Elution Buffer 6 mL
    Product Manual 1
    Bench Protocol Sheet 1

    Storage & Stability

    The DNase I should be stored at -20°C upon arrival. All other components should be stored dry and at room temperature.

    When stored under the recommended conditions and handled correctly, full activity of reagents is retained until the expiry date indicated on the outer box label.

    Shipping conditions

    Ambient temperature.


    The columns supplied with the ISOLATE II kits may appear similar, but each type has been optimized to work within the buffer system supplied with the corresponding kit. The swapping of columns (or buffers) between kits may lead to no recovery of nucleic acid whatsoever, or at the very least severely impaired purification.

    Interruption of the DNA/RNA extraction process is possible after the sample lysis only. It is possible to homogenize and lyse the samples and to store them in the freezer until use for RNA extraction. RNA clean up with a column cannot be interrupted and we recommend to avoid delays during the column purification process. If a delay is unavoidable the columns should be stored on ice.

    It is possible to use the ISOLATE II Plant DNA and RNA kits. The optimized lysis of these kits may be also useful for processing difficult to lyse bacteria and fungi in soil samples

    Several possibilities exist. If you are using our column based extraction kit like the ISOLATE II RNA Mini kit it would be necessary to decrease the sample amount of such samples or to increase the amount of the lysis buffer RLY to prevent clogging of the columns. Another possibility would be a pre-extraction with TRIsure (BIO-38032) and to clean up the RNA containing aqueous phase with the column based ISOLATE II RNA kits. You should follow the TRIsure protocol up to the phase separation step. Then mix the aqueous phase with a volume of ethanol and load it onto the column. From there you should proceed with the regular ISOLATE II RNA Mini kit protocol.

    These samples are treated as usual, just remove the RNAlater solution.

    We recommend the ISOLATE II Biofluids RNA kit for the extraction of cell free RNA. The kit isolates all sizes of RNA and is compatible with very limited, or challenging sample sources containing low RNA content.

    We recommend our ISOLATE II Biofluids RNA, miRNA and Plant miRNA kits. The miRNA kits are able to capture all small RNA species (<200 nt) from plant cells and tissues and to purify high quality large RNA (>200 nt) from the same sample in parallel. The ISOLATE II miRNA Kits have been developed to overcome the bias observed with small RNA isolation using phenol-based techniques, due to its proprietary small RNA separation and enrichment technology, as well as highly optimized chemistry. The Biofluids RNA kit isolates all sizes of RNA from large mRNA, viral RNA and ribosomal RNA down to small RNAs such as miRNA and siRNA. The ISOLATE II Biofluids RNA Kit is compatible with very limited, or challenging sample sources containing low RNA content.

    Agarose gel analysis of RNA samples can be both valuable and misleading. The pattern of bands on the gel can not only be indicative of the quality of the sample, but equally it can also only indicate that the gel tank, buffer or agarose is contaminated with RNase. A safer measure is to use a Bioanalyzer and look at the RIN value (RNA Integrity Number), which should be as close to 10 as possible, indicating that the RNA is not degraded. A spectrophotometer (ideally a microfluidic one) can also be used to determine the ratio of A260 to A280 for purity determination.

    All these methods give an idea of the quality of total RNA which tends to be dominated with rRNA and tRNA. It is not uncommon for an agarose gel to show an abundance of 18S and 23S rRNA but on analysis for there to be little of the transcript of interest. Ideally RNA quality control should include an assessment of the presence of common transcripts (from reference genes, such as GAPDH) using RT-PCR or RT-qPCR.

    If the yield of RNA is low, it is best to first check that all the solutions used and the equipment employed is largely free of RNase. Solutions should be prepared with the highest quality reagents available, preferably ones that have a certificate of analysis to show that they are free of DNase and RNase. If there is confidence that RNase contamination is at a minimum, then it may be worth ensuring that the sample is properly homogenised before lysis and to check a sample of the lysed material under a light microscope to ensure that all the cells are disrupted.

    RNA samples that have been contaminated with RNase (either during processing or those that have been sent from another lab) can be purified using the ISOLATE II RNA Micro Kit.