Table 2.

Histological changes in sweat glands, sebaceous glands and hair follicles with time of death.

PMI	Sweat glan	Sebaceous gland	Hair follicle
0–24 h	24-h vacuoles began to appear in the cytoplasm	No obvious change	No obvious change
36 h	Interstitial swelling occurs; the sweat gland epithelial cells become smaller	No obvious change	No obvious change
48 h	Interstitial swelling occurs; the sweat gland epithelial cells become smaller	No obvious change	No obvious change
60 h	The gland tube becomes smaller, the interstitial is swollen, and the focal cytoplasm has vacuoles	No obvious change	No obvious change
72 h	The nucleus is swollen and the cytoplasm has vacuoles	No obvious change	No obvious change
84 h	The cavity in the centre of some sweat glands disappears, the basement membrane of the sweat gland is locally swollen, and the epithelial cells are focally separated from the basement membrane	No obvious change	Occasionally, under high magnification, the cells are swollen, the hair follicles are dissolved at the roots, and the inner and outer layers of the hair follicles are separated (longitudinal section)
96 h	Epithelial cell disorder, a small amount of nuclear pyknosis, nuclear fragmentation, nuclear lysis; cell and basement membrane detachment	The sebaceous cell nucleus is irregular, and the cytoplasm begins to show flocculation changes	Hair follicle cells visible, nuclear pyknosis, nuclear fragmentation, nuclear dissolution
6 d	Epithelial cells have more nuclear pyknosis, nuclear fragmentation, nuclear lysis, and unclear cell boundaries	The sebaceous cell nucleus is dissolved, and the cytoplasm is flocculated	The gap of the hair follicle cells is widened, and the remaining changes are the same as above
8 d	Epithelial cells have more nuclear pyknosis, nuclear fragmentation, nuclear lysis, and unclear cell boundaries	The sebaceous cell nucleus is dissolved, and the cytoplasm is flocculated	The gap of the hair follicle cells is widened, and the remaining changes are the same as above
10 d	The cell hierarchy is severely disorganized, the structure of the sweat glands can still be distinguished, no normal epithelial cells, solid shrinking of the nuclei, nuclei are broken up, karyolysis	Sebaceous cell nucleus disappears	The number of hair follicle cells is reduced, and the remaining changes are the same as above
12 d	The cell hierarchy is severely disorganized, the structure of sweat glands can still be distinguished, no normal epithelial cells, shrunken solid nuclei, nuclei are broken up, karyolysis	Sebaceous cell nucleus disappears	The number of hair follicle cells are further reduced, showing more nuclear pyknosis, nuclear fragmentation, and nuclear dissolution
16 d	Residual sweat gland structure	Most of the sebocytes and basal cells are dissolved, leaving a reddish floc	Most of the hair follicle cells dissolve and disappear, leaving a small amount of nuclear pyknosis, nuclear fragmentation
20 d	Residual sweat gland structure	Most of the sebocytes and basal cells are dissolved, leaving a reddish floc	Only a few cells present, blurred hair follicle outline
24 d	Residual sweat gland structure	Sebocytes and basal cells are completely dissolved, only the sebaceous gland outline	No hair follicle structure
28 d	Residual sweat gland structure	No sebaceous gland structure	No hair follicle structure
32 d	No sweat gland structure	No sebaceous gland structure	No hair follicle structure