Version for device: MinION
Other available device versions: Flongle
Overview of the protocol
For more information about our Early Access programmes, please see this article on product release phases.
Please ensure you always use the most recent version of the protocol.
This protocol describes the step-by-step instructions to complete a rapid sequencing of genomic DNA using the Rapid Sequencing Kit V14 (SQK-RAD114). This protocol uses our most recent Kit 14 chemistry and is optimised for a fast library preparation and requires minimal laboratory equipment.
It is highly recommended that a Lambda control experiment is completed first to become familiar with the technology.
You will need to:
You will need to:
Library preparation step | Process | Time | Stop option |
---|---|---|---|
Tagmentation | Tagment your DNA using the Fragmentation Mix | 5 minutes | - |
Adapter attachment | Attach sequencing adapters to the DNA ends | 5 minutes | We strongly recommend sequencing your library as soon as it is adapted. |
Priming and loading the flow cell | Prime the flow cell and load the prepared library for sequencing | 5 minutes | - |
You will need to:
This protocol should only be used in combination with:
Lower inputs can be used but sequencing output will be reduced.
It is important that the input DNA meets the quantity and quality requirements. Using too little or too much DNA, or DNA of poor quality (e.g. highly fragmented or containing RNA or chemical contaminants) can affect your library preparation.
For instructions on how to perform quality control of your DNA sample, please read the Input DNA/RNA QC protocol.
Depending on how the DNA is extracted from the raw sample, certain chemical contaminants may remain in the purified DNA, which can affect library preparation efficiency and sequencing quality. Read more about contaminants on the Contaminants page of the Community.
We have validated and recommend the use of all the third-party reagents used in this protocol. Alternatives have not been tested by Oxford Nanopore Technologies.
For all third-party reagents, we recommend following the manufacturer's instructions to prepare the reagents for use.
We highly recommend that you check the number of pores in your flow cell prior to starting a sequencing experiment. This should be done within three months of purchasing for MinION/GridION/PromethION or within four weeks of purchasing Flongle Flow Cells. Oxford Nanopore Technologies will replace any flow cell with fewer than the number of pores in the table below, when the result is reported within two days of performing the flow cell check, and when the storage recommendations have been followed. To do the flow cell check, please follow the instructions in the Flow Cell Check document.
Flow cell | Minimum number of active pores covered by warranty |
---|---|
Flongle Flow Cell | 50 |
MinION/GridION Flow Cell | 800 |
PromethION Flow Cell | 5000 |
Note: We are in the process of reformatting our kits with single-use tubes into a bottle format.
Single-use tubes format:
Bottle format:
We recommend performing a flow cell check before starting your library prep to ensure you have a flow cell with enough pores for a good sequencing run.
See the flow cell check instructions in the MinKNOW protocol for more information.
Reagent | 1. Thaw at room temperature | 2. Briefly spin down | 3. Mix well by pipetting |
---|---|---|---|
Fragmentation Mix (FRA) | Not frozen | ✓ | ✓ |
Rapid Adapter (RA) | Not frozen | ✓ | ✓ |
Adapter Buffer (ADB) | Not frozen | ✓ | ✓ |
Reagent | Volume |
---|---|
100-150 ng template DNA | 10 μl |
Fragmentation Mix (FRA) | 1 μl |
Total | 11 μl |
Reagents | Volume |
---|---|
Rapid Adapter (RA) | 1.5 μl |
Adapter Buffer (ADB) | 3.5 μl |
Total | 5 μl |
Priming and loading the MinION and GridION Flow Cell
We recommend all new users watch the 'Priming and loading your flow cell' video before your first run.
Note: We do not recommend using any other albumin type (e.g. recombinant human serum albumin).
Note: We are in the process of reformatting our kits with single-use tubes into a bottle format. Please follow the instructions for your kit format.
Single-use tubes format:
Add 5 µl Bovine Serum Albumin (BSA) at 50 mg/ml and 30 µl Flow Cell Tether (FCT) directly to a tube of Flow Cell Flush (FCF).
Bottle format:
In a suitable tube for the number of flow cells, combine the following reagents:
Reagent | Volume per flow cell |
---|---|
Flow Cell Flush (FCF) | 1,170 µl |
Bovine Serum Albumin (BSA) at 50 mg/ml | 5 µl |
Flow Cell Tether (FCT) | 30 µl |
Total volume | 1,205 µl |
This step can be omitted if the flow cell has been checked previously.
See the flow cell check instructions in the MinKNOW protocol for more information.
We recommend using the Library Beads (LIB) for most sequencing experiments. However, the Library Solution (LIS) is available for more viscous libraries.
Reagent | Volume per flow cell |
---|---|
Sequencing Buffer (SB) | 37.5 µl |
Library Beads (LIB) mixed immediately before use, or Library Solution (LIS), if using | 25.5 µl |
DNA library | 12 µl |
Total | 75 µl |
We recommend leaving the light shield on the flow cell when library is loaded, including during any washing and reloading steps. The shield can be removed when the library has been removed from the flow cell.
Carefully place the leading edge of the light shield against the clip.
Note: Do not force the light shield underneath the clip.
Gently lower the light shield onto the flow cell. The light shield should sit around the SpotON cover, covering the entire top section of the flow cell.
Data acquisition and basecalling
Once you have loaded your flow cell, the sequencing run can be started on MinKNOW, our sequencing software that controls the device, data acquisition and real-time basecalling. For more detailed information on setting up and using MinKNOW, please see the MinKNOW protocol.
MinKNOW can be used and set up to sequence in multiple ways:
For more information on using MinKNOW on a sequencing device, please see the device user manuals:
To start a sequencing run on MinKNOW:
1. Navigate to the start page and click Start sequencing.
2. Fill in your experiment details, such as name and flow cell position and sample ID.
3. Select the sequencing kit used in the library preparation on the Kit page.
4. Configure the sequencing and output parameters for your sequencing run or keep to the default settings on the Run configuration tab.
Note: If basecalling was turned off when a sequencing run was set up, basecalling can be performed post-run on MinKNOW. For more information, please see the MinKNOW protocol.
5. Click Start on the Review page to start the sequencing run.
After sequencing has completed on MinKNOW, the flow cell can be reused or returned, as outlined in the Flow cell reuse and returns section.
After sequencing and basecalling, the data can be analysed. For further information about options for basecalling and post-basecalling analysis, please refer to the Data Analysis document.
In the Downstream analysis section, we outline further options for analysing your data.
Flow cell reuse and returns
The Flow Cell Wash Kit protocol is available on the Nanopore Community.
Instructions for returning flow cells can be found here.
Note: All flow cells must be flushed with deionised water before returning the product.
Downstream analysis
There are several options for further analysing your basecalled data:
For in-depth data analysis, Oxford Nanopore Technologies offers a range of bioinformatics tutorials and workflows available in EPI2ME. The platform provides a vehicle where workflows deposited in GitHub by our Research and Applications teams can be showcased with descriptive texts, functional bioinformatics code and example data.
Oxford Nanopore Technologies' Research division has created a number of analysis tools, which are available in the Oxford Nanopore GitHub repository. The tools are aimed at advanced users, and contain instructions for how to install and run the software. They are provided as-is, with minimal support.
If a data analysis method for your research question is not provided in any of the resources above, please refer to the Bioinformatics section of the Resource centre. Numerous members of the Nanopore Community have developed their own tools and pipelines for analysing nanopore sequencing data, most of which are available on GitHub. Please be aware that these tools are not supported by Oxford Nanopore Technologies, and are not guaranteed to be compatible with the latest chemistry/software configuration.
Issues during DNA/RNA extraction and library preparation
We also have an FAQ section available on the Nanopore Community Support section.
If you have tried our suggested solutions and the issue still persists, please contact Technical Support via email (support@nanoporetech.com) or via LiveChat in the Nanopore Community.
Observation | Possible cause | Comments and actions |
---|---|---|
Low DNA purity (Nanodrop reading for DNA OD 260/280 is <1.8 and OD 260/230 is <2.0–2.2) | The DNA extraction method does not provide the required purity | The effects of contaminants are shown in the Contaminants document. Please try an alternative extraction method that does not result in contaminant carryover. Consider performing an additional SPRI clean-up step. |
Low RNA integrity (RNA integrity number <9.5 RIN, or the rRNA band is shown as a smear on the gel) | The RNA degraded during extraction | Try a different RNA extraction method. For more info on RIN, please see the RNA Integrity Number document. Further information can be found in the DNA/RNA Handling page. |
RNA has a shorter than expected fragment length | The RNA degraded during extraction | Try a different RNA extraction method. For more info on RIN, please see the RNA Integrity Number document. Further information can be found in the DNA/RNA Handling page. We recommend working in an RNase-free environment, and to keep your lab equipment RNase-free when working with RNA. |
Observation | Possible cause | Comments and actions |
---|---|---|
Low recovery | DNA loss due to a lower than intended AMPure beads-to-sample ratio | 1. AMPure beads settle quickly, so ensure they are well resuspended before adding them to the sample. 2. When the AMPure beads-to-sample ratio is lower than 0.4:1, DNA fragments of any size will be lost during the clean-up. |
Low recovery | DNA fragments are shorter than expected | The lower the AMPure beads-to-sample ratio, the more stringent the selection against short fragments. Please always determine the input DNA length on an agarose gel (or other gel electrophoresis methods) and then calculate the appropriate amount of AMPure beads to use. ![]() |
Low recovery after end-prep | The wash step used ethanol <70% | DNA will be eluted from the beads when using ethanol <70%. Make sure to use the correct percentage. |
Issues during the sequencing run using a Rapid-based sequencing kit
We also have an FAQ section available on the Nanopore Community Support section.
If you have tried our suggested solutions and the issue still persists, please contact Technical Support via email (support@nanoporetech.com) or via LiveChat in the Nanopore Community.
Observation | Possible cause | Comments and actions |
---|---|---|
MinKNOW reported a lower number of pores at the start of sequencing than the number reported by the Flow Cell Check | An air bubble was introduced into the nanopore array | After the Flow Cell Check it is essential to remove any air bubbles near the priming port before priming the flow cell. If not removed, the air bubble can travel to the nanopore array and irreversibly damage the nanopores that have been exposed to air. The best practice to prevent this from happening is demonstrated in this video. |
MinKNOW reported a lower number of pores at the start of sequencing than the number reported by the Flow Cell Check | The flow cell is not correctly inserted into the device | Stop the sequencing run, remove the flow cell from the sequencing device and insert it again, checking that the flow cell is firmly seated in the device and that it has reached the target temperature. If applicable, try a different position on the device (GridION/PromethION). |
MinKNOW reported a lower number of pores at the start of sequencing than the number reported by the Flow Cell Check | Contaminations in the library damaged or blocked the pores | The pore count during the Flow Cell Check is performed using the QC DNA molecules present in the flow cell storage buffer. At the start of sequencing, the library itself is used to estimate the number of active pores. Because of this, variability of about 10% in the number of pores is expected. A significantly lower pore count reported at the start of sequencing can be due to contaminants in the library that have damaged the membranes or blocked the pores. Alternative DNA/RNA extraction or purification methods may be needed to improve the purity of the input material. The effects of contaminants are shown in the Contaminants Know-how piece. Please try an alternative extraction method that does not result in contaminant carryover. |
Observation | Possible cause | Comments and actions |
---|---|---|
MinKNOW shows "Script failed" | Restart the computer and then restart MinKNOW. If the issue persists, please collect the MinKNOW log files and contact Technical Support. If you do not have another sequencing device available, we recommend storing the flow cell and the loaded library at 4°C and contact Technical Support for further storage guidance. |
Observation | Possible cause | Comments and actions |
---|---|---|
Pore occupancy <40% | Not enough library was loaded on the flow cell | Ensure the correct concentration of good quality library is loaded on to a MinION Mk1B/GridION flow cell. To check the concentration, please refer to the library preparation protocol. Please quantify the library before loading and calculate mols using tools like the Promega Biomath Calculator, choosing "dsDNA: µg to pmol" |
Pore occupancy close to 0 | The Rapid Sequencing Kit V14/Rapid Barcoding Kit V14 was used, and sequencing adapters did not attach to the DNA | Make sure to closely follow the protocol and use the correct volumes and incubation temperatures. A Lambda control library can be prepared to test the integrity of reagents. |
Pore occupancy close to 0 | No tether on the flow cell | Tethers are adding during flow cell priming (FCT tube). Make sure FCT was added to FCF before priming. |
Observation | Possible cause | Comments and actions |
---|---|---|
Shorter than expected read length | Unwanted fragmentation of DNA sample | Read length reflects input DNA fragment length. Input DNA can be fragmented during extraction and library prep. 1. Please review the Extraction Methods in the Nanopore Community for best practice for extraction. 2. Visualise the input DNA fragment length distribution on an agarose gel before proceeding to the library prep. ![]() 3. During library prep, avoid pipetting and vortexing when mixing reagents. Flicking or inverting the tube is sufficient. |
Observation | Possible cause | Comments and actions |
---|---|---|
Large proportion of unavailable pores (shown as blue in the channels panel and pore activity plot) ![]() |
Contaminants are present in the sample | Some contaminants can be cleared from the pores by the unblocking function built into MinKNOW. If this is successful, the pore status will change to "sequencing pore". If the portion of unavailable pores stays large or increases: 1. A nuclease flush using the Flow Cell Wash Kit (EXP-WSH004) can be performed, or 2. Run several cycles of PCR to try and dilute any contaminants that may be causing problems. |
Observation | Possible cause | Comments and actions |
---|---|---|
Large proportion of inactive/unavailable pores (shown as light blue in the channels panel and pore activity plot. Pores or membranes are irreversibly damaged) | Air bubbles have been introduced into the flow cell | Air bubbles introduced through flow cell priming and library loading can irreversibly damage the pores. Watch the Priming and loading your flow cell video for best practice |
Large proportion of inactive/unavailable pores | Certain compounds co-purified with DNA | Known compounds, include polysaccharides, typically associate with plant genomic DNA. 1. Please refer to the Plant leaf DNA extraction method. 2. Clean-up using the QIAGEN PowerClean Pro kit. 3. Perform a whole genome amplification with the original gDNA sample using the QIAGEN REPLI-g kit. |
Large proportion of inactive/unavailable pores | Contaminants are present in the sample | The effects of contaminants are shown in the Contaminants Know-how piece. Please try an alternative extraction method that does not result in contaminant carryover. |
Observation | Possible cause | Comments and actions |
---|---|---|
Temperature fluctuation | The flow cell has lost contact with the device | Check that there is a heat pad covering the metal plate on the back of the flow cell. Re-insert the flow cell and press it down to make sure the connector pins are firmly in contact with the device. If the problem persists, please contact Technical Services. |
Observation | Possible cause | Comments and actions |
---|---|---|
MinKNOW shows "Failed to reach target temperature" | The instrument was placed in a location that is colder than normal room temperature, or a location with poor ventilation (which leads to the flow cells overheating) | MinKNOW has a default timeframe for the flow cell to reach the target temperature. Once the timeframe is exceeded, an error message will appear and the sequencing experiment will continue. However, sequencing at an incorrect temperature may lead to a decrease in throughput and lower q-scores. Please adjust the location of the sequencing device to ensure that it is placed at room temperature with good ventilation, then re-start the process in MinKNOW. Please refer to this FAQ for more information on MinION Mk 1B temperature control. |
Purchase a MinION Starter Pack from Avantor to get full community access and benefit from:
Already have a Nanopore Community account?
Log in hereRequest a call with our experts for detailed advice on implementing nanopore sequencing.
Request a callVisit our microbial sequencing spotlight page on vwr.com.
Microbial sequencingWe use cookies and similar technologies on our websites to help provide you with the best possible online experience.
By using our sites and apps, you agree that we may store and access cookies and similar technologies on your device.