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Cat. No.
500 x 50µl Reactions

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ImmoMix™ is a complete ready-to-use, red-colored, high yield; heat-activated, 2x reaction-mix which simply requires the user to add water, template and primers, and then pre-heat to 95°C for 10 minutes to carry out successful PCR assays. Once completed, the reaction mix can be loaded directly on to a gel.

Product Highlights

  • Convenient - pre-mixed, pre-optimized 2x solution
  • Ready to use format - reduces risk of contamination
  • Fast set up - decreased time compared to traditional methods
  • Red color - indicates the mix has been added
  • Direct gel loading - no further processing necessary

Product Description

ImmoMix™ Red is a complete ready-to-use heat-activated 2x reaction-mix, which simply requires the user to add only water, template and primers, and then pre-heat to 95°C for 10 minutes to successfully carry out PCR assays. The 10 minute activation step eliminates the presence of non-specifics such as primer-dimers and mis-primed products, since the enzyme is inactive at initial low temperatures.

ImmoMix Red combines all of the features and advantages of ImmoMix and contains an additional inert red dye. This non-toxic, non-hazardous red dye allows users to load samples directly onto a gel, without the need to add loading buffer since the mix is of sufficiently high density to sink to the bottom of the gel.

Adequate mixing is also ensured when reactions are set up. The red dye migrates like a 350 bp fragment on a 2% agarose TAE gel (or 600 bp on a 1% agarose).

ImmoMix Red is based on IMMOLASE™ DNA Polymerase, which leaves an ´A´ overhang and can be used for a wide variety of templates. An additional 50 mM MgCl2 solution is included should any fine adjustments be required.

ImmoMix Red reduce the time needed to set up reactions, thereby reducing the risk of contamination. Greater reproducibility is ensured, by reducing the number of pipetting steps that can lead to pipetting errors.


  • Ultra-high specificity for multiplex reactions
  • Products suitable for TA cloning

PCR Enzyme Guide

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PCR Selection Chart

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500 Reactions

ImmoMix Red

10 x 1.25 mL

50 mM MgCl2 Solution

1.2 mL


  • BIO-25022: 500 x 50 µL Reactions 10 x 1.25 mL


  • 2x

Storage & Stability

All components should be stored at -20°C upon receipt for optimum stability. Repeated freeze/thaw cycles should be avoided.

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

Components may also be stored at +4°C and will remain stable for up to 2 weeks, however storage at -20°C is recommended.

Shipping conditions

On Dry Ice or Blue Ice.


Meridian's mixes contain magnesium chloride at the following concentrations (please see table below). An additional tube of 50 mM MgCl2 solution is supplied with each mix to facilitate further optimization if required.

 Meridian Mix Final Magnesium Concentration
ACCUZYME Mix  2.0 mM.
BioMix / BioMix Red  2.5 mM.
ImmoMix / ImmoMix Red  3.0 mM.
BIO-X-ACT Short Mix  2.0 mM.
MangoMix  2.5 mM.
MyTaq  3.0 mM.
RANGER  1.5 mM.

IMMOLASE DNA Polymerase requires a heat-activation step of 10 minutes at 95°C.

As well as most standard applications, IMMOLASE DNA Polymerase is ideally suited to the following:

-          High-throughput applications

-          Multiplex PCR

-          TA Cloning

IMMOLASE DNA Polymerase has been manufactured under 13485 Quality Management System and is suitable for further manufacturing use as an IVD component.

The features of IMMOLASE DNA Polymerase are as follows:

  • Heat Activation: 10 minutes at 95°C
  • Speed: 15-30 s/kb (template dependant)
  • Length amplified: Around 5 kb (genomic DNA)

Optimal Extension Temperature: 72°C

At Meridian we pride ourselves in supplying high-quality polymerases to suit your requirements. To aid your selection of the most suited enzyme for your specific applications, please see our enzyme selection tool.

All our polymerases are guaranteed for a period of 12 months from the date of purchase. These should be stored at -20°C during this time for optimal retention of activity.

Please Note: We do not recommend the storage of our polymerases at -80 °C as ice crystals could form on the active site, which may affect or destroy the activity of the enzyme.

PCR can be a challenging technique, with various parameters to optimize to achieve the best results. If you are having problems, these could be easily resolved by addressing a few issues. Please see our PCR troubleshooting guide for suggestions and help with your specific problems.

Observation Recommended Solution(s)
No or low PCR yield  Enzyme concentration too low – increase the amount of enzyme in 0.5 U increments.
 Primers degraded – check quality and age of the primers.
 Magnesium concentration too low – increase concentration in 0.25 mM increments with a starting  concentration of 1.75 mM.
 Primer concentration not optimized. Titrate primer concentration (0.3-1 µM); ensuring that both  primers have the same concentration.
 Template concentration too low – Increase concentration of template.
 Perform a positive control to ensure that the enzyme, dNTPs and buffers are not degraded and/or contaminated.
Multiple Bands  Primer annealing temperature too low. Increase annealing temperature. Primer annealing should be at least 5°C below the calculated Tm of primers.
 Prepare master mixes on ice or use a heat-activated polymerase.
 For problems with low specificity. Try adding 3% DMSO (not supplied) to improve specificity.
Smearing or artifacts  Template concentration too high. Prepare serial dilutions of template.
 Too many cycles. Reduce the cycle number by 3-5 to remove non-specific bands.
 Enzyme concentration too high - decrease the amount of enzyme in 0.5 U increments.
 Extension time too long. Reduce extension time in 0.5-1 minute increments.

These terms refer to parameters to be considered when performing PCR and are important features in selecting the correct enzyme for your needs. Understanding what they mean is therefore crucial: Yield: The amount of DNA produced in a PCR reaction. Fidelity: The accuracy of the enzyme at incorporating the correct dNTP to the elongating DNA strand. Processivity: The length of time a polymerase is associated with the template and therefore the size of fragment which can be amplified. Specificity: A measure of the unwanted by-products generated in a reaction.

During PCR setup at room temperature, standard polymerases will have some activity. When using a hot-start polymerase, this enzyme will have no activity at room temperature, thus reducing the risk of unspecific products in the reaction due to these mis-primed oligonucleotides. This feature makes this type of polymerase ideally suited to high-throughput applications, where the reactions may be left sitting at room temperature for prolonged periods of time.

In nature, the ability of a DNA polymerase to correct misincorporations of nucleotides in the DNA strand being elongated is often crucial to the survival of the host organism. This ability is termed "proofreading activity" and occurs in the 3' to 5' direction. This activity also leads to the polymerase removing unpaired nucleotides overhanging at the 3'end (A-overhangs), creating blunt ends.

One unit is defined as the amount of enzyme that incorporates 10 nmoles of dNTPs into acid-insoluble form in 30 minutes at 72°C.

All Meridian polymerases are available in the convenient format of a 2x master mix, containing all the reagents and additives necessary to perform successful PCR, with the exception of template, primers and water. This formulation not only provides a convenient and hassle-free PCR setup, but also significantly reduces the chances of human error, inaccuracies and contamination by reducing the pipetting steps required.

We recommend a final reaction volume of 50 µL, this requiring the use of 25 µL of the 2x master mix and to make up to 50 µL using template, primers and PCR grade water.

Whilst the exact composition of the mixes is proprietary information, all mixes are made up of reaction buffer, magnesium, dNTPs, polymerase and additives, designed to keep the polymerase stable in the mix, as well as provide the optimal conditions for PCR.

All Meridian PCR mixes come supplied at a 2x concentration, requiring the user simply to add template, primers and PCR grade water to a final concentration of 1x.

If possible, we would recommend an additional cleanup of affected samples, for instance, customers had very good experiences with the clean-up of samples containing humic acids with SureClean Plus. Alternatively decreasing the template concentration will help to minimize the amount of inhibitors. The amount of primer can be increased, but do not exceed the suggested limits.

No, the dyes and composition of the Red Reaction Buffers and Mixes are such that the samples will sink easily into the well and the samples can be clearly seen, thus no loading buffer is required to load your samples on an agarose gel.

The dye present in the Red Mixes or Red Reaction Buffers does not interfere with PCR product isolation procedures or subsequent applications like sequencing. An exception is the quantification of PCR products in colored buffers with photometric methods or fluorescence assays. We cannot exclude the impact of the dye on quantification results and suggest the purification of these samples, for instance with ISOLATE II PCR & Gel kit or SureClean Plus.