The value of the Lugol's iodine staining technique for the identification of vaginal epithelial cells

Abstract

This paper reports on the specificity of the Lugol's iodine staining technique for the detection of vaginal epithelial cells on penile swabs. Air-dried swabs taken from the glans of the penis of 153 hospital patients and from 50 healthy volunteers, whose last sexual intercourse had taken place at least 5 days previously, were stained with Lugol's solution. Glycogenated cells were found in more than 50% of the cases studied, even in healthy volunteers without urethritis. In almost all of these cases the smear contained at least a few polygonal nucleated epithelial cells showing an unequivocal positive Lugol reaction. These cells cannot be distinguished from superficial or intermediate vaginal cells, by cytomorphology or staining. Urinary tract infections had no influence on the glycogen content of male squamous epithelial cells. On the basis of these results the Lugol's method can no longer be assumed to prove the presence of vaginal cells in penile swabs.

Identification of Body Fluid Stains Using Real-time RT-PCR: Discrimination Between Salivary, Nasal, and Vaginal Secretions

“…19 22) Lugol's staining technique has long been used as a speciˆc test for vaginal squamous cells, 21,22) but is no longer considered su‹ciently speciˆc since glycogen-containing cells exist in male oral and urethral squamous cells. 23,24) In addition, most laboratories do not have speciˆc antibody reserves.…”

A novel histological technique for distinguishing between epithelial cells in forensic casework

“…The expression of various mucins and glycogen in epithelial cells is well known [1,[6][7][8][10][11][12][13][14][15][16]. Mucins belong to a family of mucopolysaccharides that protect the epithelial cell lining of the vagina and are either present on the cell surface of superficial epithelium or secreted [11].…”

“…One of the most promising techniques, first reported in the 1970s, was Lugol's iodine that identified vaginal cells by the presence of glycogen granules [6][7][8]. However, the absolute specificity of this technique has since been questioned, with several studies demonstrating the presence of glycogenated squamous cells also in oral mucosa, the male urinary tract and on the glans penis [6][7][8]. The approach is therefore now deemed unsuitable for use in forensic laboratories.…”

“…Several previous studies have examined differential carbohydrate and protein expression including the immunohistochemical detection of cytokeratins, estrogen receptors and phosphodiesterases but no unique marker has been identified [4,5]. One of the most promising techniques, first reported in the 1970s, was Lugol's iodine that identified vaginal cells by the presence of glycogen granules [6][7][8]. However, the absolute specificity of this technique has since been questioned, with several studies demonstrating the presence of glycogenated squamous cells also in oral mucosa, the male urinary tract and on the glans penis [6][7][8].…”

The forensic value of the immunohistochemical detection of oestrogen receptors in vaginal epithelium

“…Systematic investigations have shown that the Lugol's staining method can no longer be used as proof of the presence of vaginal cells on penile swabs from a suspected sexual offender, as glycogen-containing squamous epithelial cells can also be found in the male urethral mucosa [9][10][11]. A reliable method for the specific morphological identification of vaginal epithelial cells is not yet available.…”