A new auto-cytoscreener has been developed bythe authors for mass screening of vaginal cytolsm.ears to detect mahgnancies of the uterine cervix.Thisdevice utilizes the size and density of nucleistained by Feulgen's reaction to ascertain rnalignantcells. The histological type of cancer of the cervix, most common in Japan, is squamous cell carcinoma.Hence, enlargement and hyperchromatism of nucleiare characteristics most expediently utilized in aut.omatic cytoanalysis.
However, the conventional processing by Feulgen's technique requires more than two hours, and itis very difficult to achieve equal staining reactionsof large numbers of samples. Therefore, the necessity of a less time consurning and rnore expedienttechnique yielding uniform staining reactions instigated the authors to develop anautomation of Feulgen's reaction. By system-programing a novel Feulgen's procedure was devised with each steprequiring a constant and equal amount of time.This constancy of all steps in the procedure facilitates readily the preparation of unlimited numbersof specimens.
The staining process by Schiff's reagent could bereduced by changing the HCl concentration in thereagent and the time of incubation. The most optimal condition of staining process was ascertainedto be at 37°C, for ten minutes, and 0.07N HCl forthe Schiff's reagent. The optimal concentration ofHCl for suitable hydrolysis was determined to be2.9 normal at 37°C. Moreover, the entire stainingprocess requires merely forty minutes, and consistedfour equal steps each of ten minutes duaration, namely, hydrolysis, staining, rinse, and clearingfor mounting.
Each step was followed by a double rinse fortwenty sec. to forestall contamination, preparingthe srnear for next step.
Cervical cyto-srnears prepared by this newly developed autornated modification of Feulgen's staining method were compared with those prepared bythe conventional technique, ernploying on ZeissU.M.S.P.
Thirty nuclei of superficial cells were scannedin each stained specimen at the wave length of570n.m.and the integrations of absorption werecornputed. Differences in the quality of stainingbetween specirnens processed by either proceduredid not occur.
The shortened modification of the technique proved to either be as efficient and reliable as thelonger conventional procedure.
