Immunocytochemistry (ICC) — Step-by-Step Protocol (Bio-Techne)

critical

Reversed Fixation and Permeabilization Order

Poor cell morphology, increased autofluorescence, or loss of intracellular antigens when permeabilization is performed before fixation.

💡 4 · ✓ 4

severe

Incorrect Permeabilization Method for Target Location

Weak or absent staining of nuclear transcription factors when using detergent-based permeabilization, or poor cytoplasmic protein detection with alcohol-based methods.

💡 4 · ✓ 4

severe

Failed Intracellular Antigen Detection After Fixation

Intracellular markers such as cytokines, transcription factors, or phosphoproteins show no signal despite proper antibody validation. Surface markers stain normally, but internal targets remain undetected indicating permeabilization issues.

💡 4 · ✓ 5

severe

Lack of Antibody-Specific Protocol Validation

Inconsistent or failed staining when applying generic fixation/permeabilization protocols to different antibodies, especially transcription factors. Expected positive populations are negative or dim.

💡 4 · ✓ 4

moderate

Photobleaching During Fixation and Storage

Progressive loss of fluorescence signal over time, particularly noticeable in samples fixed and stored for later analysis. Light-sensitive fluorophores show dramatically reduced intensity.

💡 4 · ✓ 4