• Product name
    Proteinase K
  • Tested applications
    Suitable for: IHC-P, In situ hybridizationmore details
  • General notes


    1. IHC procedure: Incubate tissue section for 5 to 7 minutes at room temperature; Rinse and proceed with immunostaining.
    2. General ISH procedure: Incubate tissue section for 15 minutes at 37oC; Rinse and proceed with hybridization.


    ab64220 is provided as a single component, ready-to-use solution.


  • Form
  • Storage instructions
    Store at -20°C. Stable for 12 months at -20°C
  • Storage buffer
    pH: 7.2
    Preservative: 0.1% Sodium azide
    Constituent: Tris buffer
  • Concentration information loading...
  • Research areas
  • Relevance
    Proteinase K is an endolytic protease that cleaves peptide bonds preferentially next to the carboxyl group of N-substituted hydrophobic aliphatic and aromatic amino acids. Proteinase K is classified as a serine protease and exhibits broad substrate specificity. It can hydrolyze keratin; hence the name. Proteinase K is used for the digestion of proteins on tissue sections as a pre-treatment to aid in the preparation of mRNA and its detection by in situ hybridisation methods using oligonucleotide probes.
  • Alternative names
    • Endopeptidase K
    • Tritirachium alkaline proteinase


Our Abpromise guarantee covers the use of ab64220 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
IHC-P Use at an assay dependent dilution.
In situ hybridization Use at an assay dependent dilution.


This product has been referenced in:
  • Plebanek MP  et al. Pre-metastatic cancer exosomes induce immune surveillance by patrolling monocytes at the metastatic niche. Nat Commun 8:1319 (2017). IHC-P ; Mouse . Read more (PubMed: 29105655) »
  • Li H  et al. The superior regenerative potential of muscle-derived stem cells for articular cartilage repair is attributed to high cell survival and chondrogenic potential. Mol Ther Methods Clin Dev 3:16065 (2016). IHC ; Mouse . Read more (PubMed: 27990446) »

See all 2 Publications for this product

Customer reviews and Q&As

fast and easy

Excellent Excellent 5/5 (Ease of Use)
Proteinase K digestion has worked well for cytokeratin 20 (ab854) staining.
The enzyme is ready to use and requires a maximum of 15 minutes for digestion.

Abcam user community

Verified customer

Submitted Feb 08 2018

I can confirm that the Proteinase K (ab64220) is provided at 0.2 mg/ml, this is 200 ug/ml proteinase K. This can be used directly or diluted further if neccessary.

Thank you for contacting Abcam.

We spoke earlier about two antibodies:
anti-BMPR2 ab78422 (https://www.abcam.com/bmpr2-antibody-mm0060-9a10-ab78422.html)
anti-TRPM8 ab109308 (https://www.abcam.com/trpm8-antibody-epr41962-ab109308.html)...

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Thank you for contacting us.

The concentration of proteinase K is approximately 200 ug/ml. For the 10ug/ml working dilution that you said you want for in situ hybridization, you will need to dilute it 1/20.

I hope this information...

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Thank you for contacting us.
I am sorry to hear that the antibodie might not be working as expected.

As we discussed over the phone the following troubleshooting tips might help in finding the cause of the problem:

1) Try antig...

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Thank you for your inquiry.

We have a number of products that are comparable with the products on the list you sent us. For future inquiriesI would like to direct you to the search facility on our website (www.abcam.com).

Please e...

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Thank you for your reply.

In theory, the proteinase K could also be used in DNA preparation. However, please not that this has not been tested. This reagent is sold as an antigen retrieval buffer.

I hope this will be helpful. If y...

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Thank you for your enquiry, I am pleased to help.

From what I understand here, the customer would liketo detect the HA tag on their recombinant protein expressed in cell culture. This is Immunocytochemistry (ICC). I have reviewed the selecti...

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Thank you for contacting Abcam. I have inquired to the lab about the concentration of Proteinase K in this product and have been told it is w/v. This product may be used directly as an antigen retrieval system for IHC. Incubate for 5-7 minutes at ro...

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Thank you for contacting us.

Thank you for making us aware of the oversight in the IHC handbook. I have been searching through our recommended protocols for antigen retrieval using Proteinase K but have not found an Abcam recommendation fo...

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