Protocol Citation: Dylan P. Smith, Kabir G. Peay, Gail Ackermann, Amy Apprill, Markus Bauer, Donna Berg-Lyons, Jason Betley, T. D. Bruns, J. Greg Caporaso, Noah Fierer, Louise Fraser, Jed A. Fuhrman, M. Gardes, Jack A. Gilbert, Niall Gormley, Greg Humphrey, James Huntley, Janet K. Jansson, Rob Knight, Chris L. Lauber, S. Lee, Sarah M. Owens, Alma E. Parada, Geoff Smith, J. Taylor, Luke Thompson, Willam A. Walters, T. J. White 2022. Modified EMP ITS Illumina Amplicon Protocol . protocols.io https://dx.doi.org/10.17504/protocols.io.6qpvrdmeogmk/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: March 03, 2021
Last Modified: November 21, 2022
Protocol Integer ID: 47834
Abstract
The ITS protocol detailed here is designed to amplify fungal microbial eukaryotic lineages using paired-end community sequencing on the Illumina platform with primers ITS1f-ITS2 (EMP.ITSkabir).
Note: This a modified version used in biocrust project at University of California Riverside.
Guidelines
Ordering primers
The primer sequences in this protocol are always listed in the 5′ -> 3′ orientation. This is the orientation that should be used for ordering. See the page Primer Ordering and Resuspension for more information. Primer constructs were designed by Dylan Smith and Kabir Peay.
Note: Unlike the 16S and 18S sequencing primers, the ITS sequencing primers have additional 3′ bases beyond the PCR primers, in order to match the melting temperature of the Illumina adapters. The forward sequencing primer has 19 and the reverse sequencing primer has 15 additional 3′ bases; therefore the amplicon sequences will begin 19 bp (forward read) and 15 bp (reverse read) after the PCR primers.
EMP.ITSkabir forward primer (ITS1f)
Field descriptions (space-delimited):
5′ Illumina adapter
Forward primer linker
Forward primer (ITS1f; Note: This is 38 bp upstream of ITS1 from White et al., 1990.)
PCR-grade water from Sigma (cat. no. W3500) or MoBio (cat. no. 17000-11)
Platinum Hot Start PCR Master Mix (2x) from ThermoFisher (cat. no. 13000014)
Final master mix concentration in 1x reaction: 0.8x
Final primer concentration in 1x reaction: 0.2 µM
Thermocycler conditions
ITS amplification
Primers: ITS1f-ITS2
Amplicon size: ~230 bp
References
Caporaso, J. G., Lauber, C. L., Walters, W. A., Berg-Lyons, D., Huntley, J., Fierer, N., Owens, S. M., Betley, J., Fraser, L., Bauer, M., Gormley, N., Gilbert, J. A., Smith, G., & Knight, R. (2012). Ultra-high-throughput microbial community analysis on the Illumina HiSeq and MiSeq platforms. ISME J 6, 1621–1624. http://doi.org/10.1038/ismej.2012.8
Gardes, M., & Bruns, T. D. (1993). ITS primers with enhanced specificity for basidiomycetes ‐ application to the identification of mycorrhizae and rusts. Molecular Ecology, 2(2), 113–118. http://doi.org/10.1111/j.1365-294X.1993.tb00005.x
Smith, D. P., & Peay, K. G. (2014). Sequence depth, not PCR replication, improves ecological inference from next generation DNA sequencing. PLoS ONE, 9(2), e90234–e90234. http://doi.org/10.1371/journal.pone.0090234
Walters, W., Hyde, E. R., Berg-Lyons, D., Ackermann, G., Humphrey, G., Parada, A., Gilbert, J. A., Jansson, J. K., Caporaso, J. G., Fuhrman, J. A., Apprill, A., & Knight, R. (2016). Improved bacterial 16S rRNA gene (V4 and V4-5) and fungal internal transcribed spacer marker gene primers for microbial community surveys. mSystems, 1(1), e00009–15. http://doi.org/10.1128/mSystems.00009-15
White, T. J., Bruns, T., Lee, S., & Taylor, J. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In PCR protocols: a guide to methods and applications (pp. 315–322). New York: Academic Press.
Materials
MATERIALS
PCR-Grade WaterSigma AldrichCatalog #W3500
Platinum Hot Start PCR Master Mix (2x)Thermo Fisher ScientificCatalog #13000014
UltraClean PCR Clean Up KitMobioCatalog #12500-250-1
Safety warnings
Please refer to the SDS (Safety Data Sheet) for safety and hazard information.
Before start
For running these libraries on the MiSeq and HiSeq, please make sure you read the supplementary methods of Caporaso et al. (2012). You will need to make your sample more complex by adding 5-10% PhiX to your run.
Amplification Protocol
Amplification Protocol
Amplify samples in triplicate.
Note
Each sample will be amplified in 3 replicate 25-µL PCR reactions.
Pool triplicate PCR reactions for each sample into a single volume (75 µL). Do not combine amplicons from different samples at this point.
Run amplicons from each sample on an agarose gel.
Note
Low-biomass samples may yield faint or no visible bands; alternative methods such as a Bioanalyzer could be used to verify presence of PCR product.
Expected result
Expected band size for ITS1f-ITS2 is ~230 bp.
Quantify amplicons (DNA concentration) with NanoDrop spectrophotometer.
Clean up the amplicons using magnetic bead clean up. Please contact Matthew Collin matthew.collin@ucr.edu for the bead clean up protocol.
Combine an equal amount of amplicon from each sample (240 ng) into a single, sterile tube. Higher amounts can be used if the final pool will be gel-isolated or when working with low-biomass samples.
Note
When working with multiple plates of samples, it is typical to produce a single tube of amplicons for each plate of samples.
Measure concentration and A260/A280 ratio of final pool that has been cleaned.
Expected result
For best results the A260/A280 ratio should be between 1.8-2.0.
Send an aliquot for sequencing along with sequencing primers listed below.