Histological techniques used in the assessment of rectal tissue
| Technique | Target and brief utility |
| Tinctorial stains | |
| H&E on multiple blocks/levels | General structure |
| Elastic van Gieson | Connective tissue (collagen, elastin) |
| Congo red | Amyloid |
| Periodic acid-Schiff±diastase | Carbohydrates and mucins |
| Immunostains | |
| MTOCH1* | Identification and quantification of neurons and cell morphology (diagnosis of aganglionosis, hypoganglionosis and hyperganglionosis) |
| c-Kit (CD117) | Interstitial cells of Cajal, mast cells |
| CD45/CD3 | White cells/T lymphocytes: to clarify nature of inflammatory infiltrates in ganglionitis or leiomyositis |
| Alpha smooth muscle actin and desmin | Confirm myocyte loss in myopathies; specific deficiency may also accompany some forms of gastrointestinal neuromuscular diseases |
*Alternative to the London classification,21 which recommends NSE, PGP9.5 or Hu C/D.