HiDi® (pronounced “Heidi”) stands for highly discriminating.1 A highly discriminating  enzyme is an enzyme that’s been artificially modified to work in highly selective PCR testing and mutation detection.1 They are the gold standard for cases where a researcher or healthcare provider is tasked with ‘finding a needle in a haystack’, delivering a level of certainty that other products can’t provide.1 

What Are HiDi® Enzymes and What Sets Them Apart?

A HiDi® enzyme differentiates between primers that bind to their intended targets versus primers that are not fully binding.1 In simple terms, the enzyme discards any mismatched primers and only ‘searches’ for the primers that are fully matched to the enzyme’s target sequences.1 

Many enzymes on the market today feature low discrimination or none at all.1 This becomes an issue when tests need to focus on specific primers, e.g. in as-PCR testing.1 

Highly discriminating enzymes, on the other hand, are exceptionally useful in these cases.1

Click here for a complete list of abbreviation definitions

3 Applications for HiDi® enzymes:

1. Genotyping

HiDi® enzymes can be used in genotyping to determine the alleles (genetic variants) an individual might have inherited.1-3

HiDi® gives testers key advantages in genotyping:2

  • Up to 30% total time and labor cost reduction compared to PCR- and NGS-based genotyping
  • No significant protocol changes required
  • Enables confident acceleration of research

2. Cancer mutation detection

HiDi® products can be used in as-PCR testing to detect cancer mutations.1,2 

The traditional PCR workflow would include primer design, followed by PCR testing, followed by separation of DNA fragments (gel electrophoresis).2,4 With HiDi®, the workflow is shorter, starting with primer design and progressing straight to quantitative (real-time) PCR.2 qPCR can simultaneously amplify and detect the target DNA.5

3. CRISPR-Cas SNP quality control
SNPs can provide crucial information about an individual’s genetic makeup and indicate their predisposition towards certain diseases.2 SNPs introduced by CRISPR technology must undergo quality control filtering which can be done by HiDi very efficiently.1

The traditional CRISPR workflow for SNP quality control takes up to 60 days, but the workflow using HiDi® DNA polymerase only takes just over 40 days.2

This means:2 

  • 20% less time required
  • 20% labor cost reduction
  • 60% overall total workflow cost reduction
  • 50% less plastic consumable waste used
  • 65% lower cost associated with external services

HiDi® Applications in HLA Typing and Matching and in Liquid Biopsies

HiDi® enzymes are valuable in HLA typing and matching, helping to test patients and donors for bone marrow and cord blood transplant compatibility.1,6

HiDi® enzymes can also be used in liquid biopsies to detect mutations in a high background of wild-type or ‘irrelevant’ biotype sequences.1,2 This is useful for tracking the progress of a disease and testing the efficacy of treatment, e.g. the effect of chemotherapy on cancer progression.1

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HiDi® Enzymes From Medix Biochemica

There are 4 proprietary HiDi® formulations in Medix Biochemica’s HiDi® product family. These include enzymes, Taq enzymes and ready-to-use master mixes:2

What can you expect from Medix Biochemica’s HiDi® products?2

  • Excellent SNP discrimination: Differentiate alleles reliably.
  • Superior performance: Excellent for as-PCR and the first choice for highly selective PCRs. Outperform competitors.
  • Easy primer design: Standard primers, changing only the 3’ nucleotide.
  • Highly sensitive: Fewer than 10 copies of a mutation can be detected in a background of >10 000 wild-type copies.
  • No false amplification: Aptamer-based hot-start prevents false amplification and provides a fast-start function.

Benchmarking data for HiDi® Taq DNA polymerase

Benchmarking data clearly shows the benefits of Medix Biochemica’s HiDi® Taq DNA polymerase.7 

This highly selective DNA polymerase variant is specially evolved for all assays where high single nucleotide discrimination is required, e.g. as-PCR, mutation detection and genotyping.7

HiDi® Taq DNA polymerase efficiently discriminates matched primers from those that have a mismatch at the 3'-terminus.7 It outperforms competitor products in both signal generation and discrimination.7

Download ECCMID 2023 Scientific Poster

Click here to find out how the Medix Biochemica HiDi® 2x PCR Master Mix performed compared to competing products.8

HiDi® enzymes are the gold standard for high discrimination as-PCR testing, liquid biopsy and HLA typing and genotyping.2 Medix Biochemica is proud to offer HiDi® products of superior quality.

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Abbreviations Definition
as-PCR allele-specific PCR
CRISPR clustered regularly interspaced short palindromic repeats
CRISPR-Cas CRISPR-associated protein
DNA deoxyribonucleic acid
HLA human leukocyte antigen
IVD in vitro diagnostics
NGS next generation sequencing
PCR polymerase chain reaction
qPCR quantitative (real-time) PCR
SNP single-nucleotide polymorphism
Taq DNA polymerase thermostable DNA polymerase


  1. Expert opinion. Interview with Ramon Kranaster, Managing Director and R&D Director at myPOLS Biotec GmbH. May 16, 2023.  
  2. Data on file. Medix Biochemica. HiDi® Family: True gold-standard for high discrimination allele-specific PCR. February 14, 2023.
  3. Karch SB. Autopsy: molecular. In: Payne-James J, Byard RW, eds. Encyclopedia of Forensic and Legal Medicine (Second Edition). Elsevier; 2016:290-296. doi:10.1016/B978-0-12-800034-2.00041-0.
  4. Polymerase chain reaction (PCR). Khan Academy. Accessed June 13, 2023. https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/biotechnology/a/polymerase-chain-reaction-pcr.
  5. Hussain B, Yüce M, Ullah N, et al. 3 - Bioconjugated nanomaterials for monitoring food contamination. In: Grumezescu AM, ed. Nanobiosensors. Academic Press; 2017:93-127. doi:10.1016/B978-0-12-804301-1.00003-5.
  6. HLA basics. BeTheMatch.org. Published March 10, 2023. Accessed June 13, 2023. https://bethematch.org/transplant-basics/how-blood-stem-cell-transplants-work/hla-basics/.
  7. Data on file. Medix Biochemica. Benchmarking data for HiDi® Taq DNA polymerase (#9201).
  8. Data on file. Medix Biochemica 33rd ECCMID. 2023.