A SIMPLE COMBINED MICRODISSECTION AND ASPIRATION DEVICE FOR THE RAPIDPROCUREMENT OF SINGLE CELLS FROM CLINICAL PERIPHERAL-BLOOD SMEARS

Molecular analysis of cells from cytology specimens can help to establ ish a diagnosis in ambiguous cases. However, mutations in heterogeneou s samples might not be detected because of the diluting effect of DNA from normal background cells. Even ifa mutation were detected, it coul d not be traced back to a specific cell type. Molecular analysis of si ngle cells circumvents this problem. Both mechanical and laser assiste d methods have been described for the selective procurement of cells f rom histology slides; however, they have the drawback of either being technically demanding or expensive. Furthermore, it is unclear whether they can be applied to cytology specimens. Finally, few of these tech niques are able to procure single cells. Therefore, we developed a sim plified combined microdissection and aspiration device for the rapid p rocurement of single cells from clinical cytology specimens, The princ iple of this device, called the cytopicker, is the combination of the microdissection tool, a steel cannula, with the aspiration tool, a gla ss capillary connected to a vacuum, into one device. Steel cannulae ar e optimal for microdissection of cells from the hard matrix of cytolog y specimens but aspirate poorly. On the other hand, glass capillaries are suboptimal for dissecting but aspirate very well. Combining both t ools into one by inserting the capillary into the cannula allows optim al dissection using the cannula (with the glass capillary withdrawn an d thus protected), followed by optimal aspiration using the capillary (after being advanced through the cannula). All movements of the devic e are controlled by just one micromanipulator, making the cytopicker i nexpensive to manufacture. The cytopicker can rapidly and simply procu re single cells, such as lymphoblasts, from cytology specimens, such a s peripheral blood smears. DNA from these cells can be amplified by PC R. However, precautions have to be taken to avoid contamination. Once improved further, the cytopicker might facilitate molecular analysis i n the routine cytology laboratory.