A 'membranous' staining pattern in IHC indicates that the target antigen is localized to the cell membrane. Under the microscope, this appears as a distinct, continuous, or sometimes granular line outlining the borders of the cell. This pattern is biologically significant as it often identifies proteins that are integral to the cell's interaction with its environment. Common examples include: 1) **Receptor Tyrosine Kinases**: Such as HER2 (in breast cancer) or EGFR, which are transmembrane proteins involved in cell signaling. 2) **Cell Adhesion Molecules**: Like E-cadherin (in carcinomas) or CD20 (on B-cells). 3) **Surface Markers for Cell Identification**: CD3 on T-cells or CD19 on B-cells. The intensity and completeness of membranous staining (e.g., complete circumferential vs. incomplete) are often part of diagnostic scoring criteria, as seen in HER2 testing where strong, complete membranous staining in >10% of cells is scored as 3+ (positive).

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Zambia

• loveness Phiri – 1084 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies