Abstract: This invention teaches a method to identify cellular abnormalities which are associated with disease states. In one aspect, the invention is a method to distinguish premalignant and malignant stages of cervical cancer from normal cervical cells. The method utilizes infrared (IR) spectra of exfoliated cervical cells which are dried on an infrared transparent matrix and scanned at the frequency range from 3000-950 cm.sup.-1. The identification of samples is based on establishing a calibration using a representative set of spectra of normal, dysplastic and malignant specimens. During the calibration process, multivariate techniques such as Principal Component Analysis (PCA) and/or Partial Least Squares (PLS) are used. PCA and PLS reduce the data based on maximum variations between the spectra, and generate clusters in a multidimensional space representing the different populations. The utilization of Mahalinobis distances, or linear regression (e.g.

Abstract: Methods are described for determining in individuals with or without a prior history of colorectal neoplasia whether the individual has had, has, or has a risk of developing colorectal neoplasia. The method involves an assessment of the extent of apoptosis, or programmed cell death, in a colorectal biopsy specimen. Any of numerous methods to measure the extent of apoptosis in the sample is contemplated. For example, normal-appearing mucosa from the distal colon and/or rectum may be obtained from individuals undergoing screening procedures for colorectal cancer. The tissue is subjected to a method that assesses apoptosis, for example, by the extent of broken DNA ends in the nuclei of the cells in the specimen. The extent of apoptosis is expressed as a numerical ratio and indicates the possibility that an individual patient has a premalignant or malignant lesion in his or her colon or the risk for the development of a colorectal neoplasm in the future.

Abstract: The presence of anomalies is detected in exfoliated cells (e.g. in a cervical smear) using infrared spectroscopy. A beam of infrared light is directed at specimens containing cells, which may be secretions, exudates, transudates, scrapings, brushings or otherwise obtained populations of exfoliated cells of various organs or tissues, and the anomaly is detected at at least one range of frequencies by determining whether changes in infrared absorption has occurred which is due to functional group vibration in, for example, phosphodiester groups of nucleic acids, COH groups of tissue proteins, carbohydrates, or due to special arrangements of lipid molecules or abnormal lipid structures, present in the specimen.

Abstract: The presence of anomalies in biological tissues and cells in natural and cultured form (e.g. cancerous tissues or cells) is detected by infrared spectroscopy. A beam of infrared light is directed at a sample of tissues or cells in natural or cultured form containing the cells to be tested, and the anomaly is detected at at least one range of frequencies by determining whether changes in infrared absorption have occurred due to the vibration of at least one functional group of molecules present in the sample which is characteristic of the anomaly.

Abstract: A stable, single-stranded nucleoprotein filament adapted to complex specifically and stably with a target duplex DNA having a selected base sequence. The filament is composed of a single-stranded DNA probe having a region of homology with the target base sequence, and RecA protein bound stably to the DNA probe by adenosine 5'-(.gamma.-thio)triphosphate. The filament is useful in a novel system and method for enriching target duplex DNA which contains a region homologous to the probe sequence, for blocking selected restriction endonuclease sites in the target DNA, and in other DNA methodologies in which stable rapid triple-strand synaptic formation in duplex DNA can be exploited.