Automation of Blood Film Preparation and Staining Utilizing the Technicon Autoslide

Abstract

Evaluation of a prototype Technicon Autoslide, which automatically prepares, fixes, stains, dries, labels, and “coverslips” blood films, attached to a Technicon Hemalog D-90 revealed that the instrument prepares high-quality wedge blood smears with uniform distribution of leukocytes, excellent red blood cell and platelet morphology, and adequate staining of normal types of leukocytes. The fixation-staining characteristics did not enable reliable identification of some immature cell types. An additional 200 μl of blood samples is required above that required for the Hemalog D-90 in order to prepare a smear. The throughput time of the instrument, from sample aspirate to completion of the blood smear, is 14 min. One sample is completed every 45s. The final glass-slide specimen contains the blood smear sample and its identification and date, embedded in acrylic plastic, which also serves as a coverslip. The instrument can be operated by the D-90 operator with negligible additional effort. The approximate cost of each sample was 8.25 cents. The Autoslide in combination with the Hemalog D-90 should reduce technician time required to prepare, stain, and label blood smears. Its use should reduce the frequency of sample misidentification and provide more uniform quality to slide preparation and staining than is available by current manual techniques. Preliminary studies suggest that Autoslide smears are suitable for use on an image-processing type of automated differential system, and this therefore makes their use possible in a tiered screening system for detection of platelet or red cell abnormalities not recognized by the high-volume cell-counting instruments.