A new disaggregation device for cytology specimens

Abstract

A new means of disaggregating cytology specimens in suspension using an immersible rotor device is described. The new rotor is compared to an automated syringing apparatus using cervical samples. Similar results using both devices are obtained for both normal and abnormal specimens.Key terms: Cytology, specimen preparation, automation A prerequisite for the (prelscreening of cytology specimens by an automated image analysis system is a reproducible and practical method for preparing smears of disaggregated cell suspensions. Many procedures have been described (1,4,10,14,16,17), but most are limited in that they are labor-intensive or very time-consuming. To make automated cytology an attractive addition to routine manual cytology, the specimen should be handled as little as possible, and the processing time should certainly not be much longer than the time needed to prepare a cervical smear with conventional manual methods.The Biological Precision Encoding and Pattern Recognition (BioPEPR) project (19) is concerned with full automation of cervical smear prescreening, including the preparation phase. In a previous paper (lo), we described a semiautomatic procedure by which about 100 cervical smears a day could be prepared. Because it proved difficult to fully automate this entire process as it was, certain steps in the process were reevaluated in order to make a fully automated system feasible.All of the automated disaggregation systems developed to date have been automated versions of the syringing procedure (1,4,7,9,10,16). With syringing it is difficult to fully automate the changing of the needles or the syringes, and to provide adequate rinsing of the device between samples to prevent specimen contamination.The present paper describes a new method of disaggregating cell suspensions. Cell disaggregation with this device, a specially designed rotor, is easy to automate and has proved to be efficient. In this paper the rotor is described, and results obtained with this rotor when disaggregating cervical specimens are presented. MATERIALS AND METHODSCervical cells were collected as second or third scrapes using a plastic spatula that was rinsed in a preservative phosphate-buffered saline solution, containing 20% ethanol. Disaggregation was performed either by a syringing technique using a peristaltic pump device (10) for 15 min with 19-gauge needles and a speed of 55 mV min, or by a rotor immersed in the sample vial containing 9 ml of cell suspension (Fig. 1A). For comparative studies the original sample was divided before disaggregation into two to four sample containers, and the fluid volume was adjusted back to 9 ml.After disaggregation the cells were deposited onto glass microscope slides, as described elsewhere (10).The rotor device used consists of a 24-V DC Maxon motor (Sachseln, Switzerland) with a vertical axle on which different cylindrical rotor heads can be mounted. The distance from the outer edge of the rotor head to the vessel wall is about 2 mm. Figure 1B shows two examples of hollow rotor heads,...

SpinThin, a simple, inexpensive technique for preparation of thin-layer cervical cytology from liquid-based specimens

“…The current high cost of a widely advertised commercial system for preparation of slides from liquid-based cervical cytology samples led us to devise and evaluate an alternative, less costly method. It is based on principles that were developed for the preparation of monolayer cytology slides during the early years of research on automated uterine cervical cytology screening, [3][4][5] and makes use of equipment and resources generally available in the cytology laboratory.…”

Computational Cytology: Lessons Learned from Pap Test Computer-Assisted Screening

“…In parallel to these computer-based technological advances, efforts were also underway to develop a better specimen for computer analysis. A group in the Netherlands introduced a new preparation method, which would later evolve into the ThinPrep Pap Test (Hologic, then Cytyc) [10,11]. This advancement solved much of the difficulty that computers experienced with conventional smears as described above, by creating a uniform spread of cells, allowing for improved visualization of individual cell morphometry.…”

Would Monolayers Provide More Representative Samples and Improved Preparations for Cervical Screening?

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