Detection of circulating tumour cells in peripheral blood with an automated scanning fluorescence microscope.

We have developed an automated, highly sensitive and specific method for identifying and enumerating circulating tumour cells (CTCs) in the blood. Blood samples from 10 prostate, 25 colorectal and 4 ovarian cancer patients were analysed. Eleven healthy donors and seven men with elevated serum prostate-specific antigen (PSA) levels but no evidence of malignancy served as controls. Spiking experiments with cancer cell lines were performed to estimate recovery yield. Isolation was performed either by density gradient centrifugation or by filtration, and the CTCs were labelled with monoclonal antibodies against cytokeratins 7/8 and either AUA1 (against EpCam) or anti-PSA. The slides were analysed with the Ikoniscope robotic fluorescence microscope imaging system. Spiking experiments showed that less than one epithelial cell per millilitre of blood could be detected, and that fluorescence in situ hybridisation (FISH) could identify chromosomal abnormalities in these cells. No positive cells were detected in the 11 healthy control samples. Circulating tumour cells were detected in 23 out of 25 colorectal, 10 out of 10 prostate and 4 out of 4 ovarian cancer patients. Five samples (three colorectal and two ovarian) were analysed by FISH for chromosomes 7 and 8 combined and all had significantly more than four dots per cell. We have demonstrated an Ikoniscope based relatively simple and rapid procedure for the clear-cut identification of CTCs. The method has considerable promise for screening, early detection of recurrence and evaluation of treatment response for a wide variety of carcinomas.

Purification of granulosa cells from human ovarian follicular fluid using granulosa cell aggregates.

Human follicular fluid can provide a source of human granulosa cells for scientific study. However, removing potentially contaminating cells, such as white and red blood cells, is important for molecular and in vitro studies. We have developed a purification technique for human granulosa cells based on the selection of cellular aggregates. Human granulosa cells from 21 IVF patients were collected. A 50% Percoll gradient was used to remove red blood cells, and granulosa cell aggregates were collected, washed and processed for histology, electron microscopy, flow cytometry analysis, cell culture and RNA extraction. Granulosa cell aggregates were found to be homogeneous and free of white blood cells after histological and electron microscopic analysis. White blood cell contamination, measured by flow cytometry, was found to be between 2 and 4%. Polymerase chain reaction analysis revealed expression of known human granulosa cell genes and a white blood cell marker. Human granulosa cells grown in vitro showed flattened fibroblast-like morphology with lipid droplets consistent with previous reports. Cultured cells expressed the FSH receptor. Selection of human granulosa cell aggregates following centrifugation through a Percoll gradient provides an efficient method of selecting granulosa cells, suitable for both molecular and in vitro studies.