Extract-N-Amp™ Plant PCR Kits Protocol

Catalog Numbers: XNAP2, XNAP2E, and XNAR

Product Description

The Extract-N-Amp Plant PCR Kits contain all of the reagents required to rapidly extract and amplify genomic DNA from plant leaves. Briefly, the DNA is extracted from a piece of leaf tissue, a 0.5 to 0.7 cm disk cut with a standard paper punch, by incubation in the Extraction Solution at 95 °C for 10 minutes. There is no need for freezing plant tissue in liquid nitrogen, mechanical disruption, organic extraction, column purification or precipitation of the DNA. After an equal volume of the Dilution Solution is added to the extract to neutralize inhibitory substances, the extract is ready for PCR. An aliquot of the diluted extract is then combined with the Extract-N-Amp PCR Reaction Mix and user provided PCR primers to amplify target DNA.

The Extract-N-Amp PCR ReadyMix™ is a 2x reaction mix containing buffer, salts, dNTPs, and Taq polymerase. It is optimized specifically for use with the extraction reagents. This formulation uses JumpStart™ Taq antibody for specific hot start amplification, but does not contain the inert red dye found in the REDExtract-N-Amp™ PCR ReadyMix to allow detection of PCR products by methods that are sensitive to the red dye.


Reagents Provided Catalog
100 extractions,
100 amplifications
100 extractions,
500 amplifications
1,000 extractions,
1,000 amplifications
Extraction Solution E7526 12 ml 12 ml 120 ml
Dilution Solution D5688 12 ml 12 ml 120 ml
Extract-N-Amp PCR ReadyMix,
This is a 2x
PCR reaction mix containing buffer, salts, dNTPs, Taq polymerase and JumpStart Taq antibody.
E3004 1.2 ml 5 x 1.2 ml 12 ml
Collection Tubes, 2 ml T5449
2 X 50 each 2 X 50 each Not included

Reagents and Equipment Required But Not Provided

Precautions and Disclaimer

The Extract-N-Amp Plant PCR Kits are for laboratory use only. Not for drug, household or other uses. Consult the MSDS for information regarding hazards and safe handling practices.


The Extraction Solution, Dilution Solution and Extract-N-Amp PCR ReadyMix can be stored at 2-8 °C on a short-term basis, but for long-term storage, –20 °C is recommended. Do not store in a “frost-free" freezer.


All steps are carried out at room temperature unless otherwise noted.

A.    DNA extraction
       1.    Rinse the paper punch and forceps in 70% ethanol prior to use and between the handling of different

        2.    Punch a 0.5 to 0.7 cm disk of leaf tissue into a 2 ml collection tube or suitable vessel using a standard
               one-hole paper punch. If frozen plant tissue is used, keep the leaves on ice while punching disks.

        3.    Add 100 µL of the Extraction Solution to the collection tube. Close the tube and vortex briefly. Make
               sure the disk is covered by the Extraction Solution.

        4.    Incubate at 95 °C for 10 minutes. Note that leaf tissues usually do not appear to be degraded after this

        5.    Add 100 µL of the Dilution Solution and vortex to mix.

        6.    Store the diluted leaf disk at 2-8 °C. It is not necessary to remove the leaf disk before storage.

B. PCR amplification
The Extract-N-Amp PCR ReadyMix contains JumpStart Taq antibody for specific hot start amplification. Therefore, PCR reactions can be assembled at room temperature without premature Taq DNA polymerase activity.

Typical final primer concentrations are ~0.4 µM each. The optimal primer concentration and cycling parameters will depend on the system being used.

1.    Add the following reagents to a thin-walled PCR microcentrifuge tube or plate:


Reagent Volume
Water, PCR reagent x µL
Extract-N-Amp PCR
10 µL:
Forward primer y µL
Reverse primer y µL
Leaf disk extract 4 µL*
Total volume 20 µL

*Note: The Extract-N-Amp PCR ReadyMix is formulated to compensate for components in the Extraction and Dilution Solutions. If less than 4 µL of leaf disk extract is added to the PCR reaction volume, use a 50:50 mixture of Extraction:Dilution Solutions to bring the volume of leaf disk extract up to 4 µL.

2.    Mix gently and briefly centrifuge to collect all the components at the bottom of the tube.

3.    For thermal cyclers without a heated lid, add 20 µL of mineral oil to the top of each tube to prevent evaporation.

4.    The amplification parameters should be optimized for individual primers, template, and thermal cycler.

Common cycling parameters:

Step Temperature Time Cycles
Initial Denaturation 94 °C 3 minutes 1
Denaturation 94 °C 0.5-1 minutes 30-35
Annealing 45 to 68 °C 0.5-1 minutes
Extension 72 °C 1-2 minutes
(~ 1 kb/min)
Final Extension 72 °C 10 minutes 1
Hold 4 °C Indefinitely  


5.    The amplified DNA can be loaded onto an agarose gel after the PCR is completed with the addition of a separate
       loading buffer/tracking dye such as Gel Loading Buffer, Catalog Number G2526.
       Note: PCR products can be purified, if desired, for downstream applications such as sequencing with the
       GenElute™ PCR Clean-Up Kit, Catalog Number NA1020.


Related Products Catalog Numbers
Tubes for PCR Z374873, Z374962 and Z374881
PCR Marker P9577
Precast Agarose Gels P6097
TBE Buffer T4415, T6400 and T9525
Ethanol E7148, E7023 and 459836

Troubleshooting Guide

Problem Cause Solution
Little or no PCR
product is
PCR reaction may be inhibited due to contaminants in the plant extract. Dilute the extract with a 50:50 mix of extraction and dilution solutions. To test for inhibition, include a DNA control and/or spike a known amount of template (100-500 copies) into the PCR along with the plant extract.
A PCR component
may be missing or
Run a positive control to insure that components are functioning. A checklist is also recommended when assembling reactions.
There may be too few cycles performed. Increase the number of cycles (5-10 additional cycles at a time).
The annealing temperature may be too high. Decrease the annealing temperature by 2-4 °C increments
The primers may not be designed optimally. Confirm the accuracy of the sequence information. If the primers are less than 22 nucleotides long, try to lengthen the primer to 25-30 nucleotides. If the primer has a GC content of less than 45%, try to redesign the primer with a GC content of 45-60%.
The denaturation temperature may be too high or too low. Optimize the denaturation temperature by increasing or decreasing the temperature by 1 °C increments.
The denaturation time may be too long or too short. Optimize the denaturation time by increasing or decreasing it by
10 second increments.
The extension time
may be too short.
Increase the extension time by 1 minute increments, especially for long templates.
Target template is
In most cases, inherently difficult targets are due to unusually high GC content and/or secondary structure. Betaine (Product Code B 0300) has been reported to help amplification of high GC content templates at a concentration of 1.0-1.7 M.
Multiple products JumpStart Taq
antibody is not
working correctly.
Do not use DMSO or formamide with Extract-N-Amp PCR ReadyMix. It can interfere with the enzyme-antibody complex. Other cosolvents, solutes (e.g., salts) and extremes in pH or other reaction conditions may reduce the affinity of the JumpStart Taq antibody for Taq polymerase and thereby compromise its effectiveness.
Touchdown PCR
may be needed.
“Touchdown” PCR significantly improves the specificity of many PCR reactions in various applications. Touchdown PCR involves using an annealing/extension temperature that is higher than the Tm of the primers during the initial PCR cycles. The annealing/extension temperature is then reduced to the primer Tm for the remaining PCR cycles. The change can be performed in a single step or in increments over several cycles.
Contamination Reagents are
Sigma recommends that a reagent blank without DNA template be included as a control in every PCR run to determine if the reagents used in extraction or PCR are contaminated with a template from a previous reaction.




  1. Dieffenbach, C. W. and Dveksler, G. S. (Eds.) PCR Primer: A Laboratory Manual, 2nd ed., (Cold Spring Harbor Laboratory Press, New York, 2003). Catalog Number Z701270
  2. Don, R. H. et al. ‘Touchdown' PCR to circumvent spurious priming during gene amplification. Nucleic Acids Res., 19, 4008 (1991)
  3. Erlich, H. A. (Ed.) PCR Technology: Principles and Applications for DNA Amplification (Stockton Press, New York, 1989).
  4. Griffin, H. G. and Griffin, A. M. (Eds.) PCR Technology: Current Innovations, (CRC Press, Boca Raton, FL, 1994). 5. Innis, M.A., et al. (Eds.) PCR Strategies (Academic Press, New York, 1995).
  5. Innis, M., et al. (Eds.) PCR Protocols: A Guide to Methods and Applications (Academic Press, San Diego, California, 1990).
  6. Innis, M., et al. (Eds.) PCR Protocols: A Guide to Methods and Applications (Academic Press, San Diego, California, 1990).
  7. McPherson, M.J. et al. (Eds.) PCR 2: A Practical Approach (IRL Press, New York, 1995)
  8. Newton, C.R. (Ed.) PCR: Essential Data, (John Wiley & Sons, New York, 1995).
  9. Roux, K.H. Optimization and troubleshooting in PCR. PCR Methods Appl., 4, 5185-5194 (1995).
  10. Saiki, R., PCR Technology: Principles and Applications for DNA Amplification (Stockton, New York, 1989)



Use of this product is covered by one or more of the following US patents and corresponding patent claims outside the US: 5,789,224 and 5,618,711. The purchase of this product includes a limited, non-transferable immunity from suit under the foregoing patent claims for using only this amount of product for the purchaser’s own internal research. No right under any other patent claim, no right to perform any patented method, and no right to perform commercial services of any kind, including without limitation reporting the results of purchaser's activities for a fee or other commercial consideration, is conveyed expressly, by implication, or by estoppel. This product is for research use only. Diagnostic uses under Roche patents require a separate license from Roche. Further information on purchasing licenses may be obtained by contacting the Director of Licensing, Applied Biosystems, 850 Lincoln Centre Drive, Foster City, California 94404, USA.

JumpStart and JumpStart Antibody are licensed under U.S. Patent No. 5,338,671 and 5,587,287 and corresponding
patents in other countries.

GeneElute, Extract-N-Amp, JumpStart , REDExtract-N-Amp and ReadyMix are trademarks of Sigma-Aldrich Co. LLC

JC,RC,PHC 01/13-1

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