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Antigen Retrieval Solution: Protease-induced Epitope Retrieval (PIER)

Abstract:      Before the invention of heat induced antigen retrieval solution (HIER), protease-induced epitope retrieval(PIER) is the most commonly used method. Many enzymatic techniques are ever used, including trypsin, pronase, ficin, pepsin and proteinase k antigen retrieval etc.
Keywords:  Antigen Retrieval Solution, Antigen Retrieval, Enzymatic Antigen Retrieval

1. Protease-induced Epitope Retrieval

The mechanism of PIER is probably to stop the protein crosslink produced during formalin fixed process by enzymatic digestion. However, the stopping is non-specific and has negative influence on some antigens. The effect of PIER depends on the enzyme concentration and type, incubation parameters(time, temperature, pH) and fixation time. The enzymatic digestion time and fixation time are negatively correlated.

PIER Antigen Retrieval Solution

2. PIER Antigen Retrieval Solution & Optimization

FineTest and other laboratories usually optimize induced epitope retrieval condition of a few enzymes instead of trying many enzymes. FineTest adopts the ready-to-use protease K solution which has good activity at room temperature and can be applied in automated immunostaining device.

Disadvantages of PIER:

  • Not suitable for most antigens;
  • May result in morphological changes;
  • May destroy antigenic peptide

3. Enzymatic Antigen Retrieval Solution

Three enzymatic digestion methods are specified below:

3.1. Trypsin

  • Immerse the slide into 0.1% trypsin solution (pH7.8), incubate for 10-30 min at 37℃;
  • Rinse completely by running water;
  • Immunohistochemical staining

3.2. Protease

  • Drop 0.05%-0.5% (w/V) warm protease XXIV on the tissue slice and incubate for 10-25min at 37℃;
  • Rinse completely by running water;
  • Immunohistochemical staining

3.3. Pepsin

  • Immerse the slide into 0.4 % (w/V) pepsin solution;
  • Incubate for 10-25min at 37℃;
  • Rinse completely by running water;
  • Immunohistochemical staining

4. FineTest Antibody

Browse a list of FineTest antibody.

REFERENCES

Effect of Antigen Retrieval Methods on Nonspecific Binding of Antibody-Metal Nanoparticle Conjugates on Formalin-Fixed Paraffin-Embedded Tissue.