FTIR Microspectroscopic Study of Cell Types and Potential Confounding Variables in Screening

ABSTRACT: FTIR microscopy was applied to the analysis of cell types and other vari-ables present in Pap smears to ascertain the limitations of infrared spectroscopy in the diagnosis of cervical cancer and dysplasia. It was found that leukocytes, and in particu-lar lymphocytes, have spectral features in the phophodiester region (1300–900 cm01) suggestive of what has previously been described as changes indicative of malignancy. Endocervical cells and fibroblasts have similar spectral features to HeLa cells and consequently could also confound diagnosis. The use of ethanol as a fixative and dehy-drating agent results in retention of glycogen in cervical cell types and thus minimizes spectral changes in the glycogen region due to sampling technique. Spectra of seminal fluids exhibit strong bands in the phosphodiester/carbohydrate region; however, sperm contamination should be easily detectable by the presence of a distinctive doublet at 981/968 cm01. Erythrocyte spectra exhibit a reduction in glycogen band intensity, but can be discerned by a relatively low-intensity ns PO02 band. Endocervical mucin spectra exhibit a reduction in glycogen bands and a very pronounced ns PO02 band, which is similar in intensity to the corresponding band in HeLa cells. Thrombocytes have stron