Review Article

Ann Lab Med 2013; 33(1): 1-7

Published online January 1, 2013

Copyright © Korean Society for Laboratory Medicine.

Purpose and Criteria for Blood Smear Scan, Blood Smear Examination, and Blood Smear Review

Gene Gulati, Ph.D., Jinming Song, M.D., Alina Dulau Florea, M.D., and Jerald Gong, M.D.

Department of Pathology, Anatomy, and Cell Biology, Jefferson Medical College and Thomas Jefferson University Hospital, Philadelphia, USA

Correspondence to: Gene Gulati
301 Pavilion Bldg. Thomas Jefferson University Hospital, 117 South 11th Street, Philadelphia, PA 19107, USA
Tel: +1-215-955-2682
Fax: +1-215-923-6757

Received: October 12, 2012; Revised: October 23, 2012; Accepted: November 7, 2012

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


A microscopic examination of an appropriately prepared and well-stained blood smear by a knowledgeable laboratory professional is necessary and clinically useful in a number of circumstances and for a variety of reasons. In this article, an attempt is made to delineate the purpose and criteria for blood smear examination in a variety of circumstances that are encountered in everyday laboratory hematology practice. A blood smear scan serves to at least (a) verify the flagged automated hematology results and (b) determine if a manual differential leukocyte count needs to be performed. Blood smear examination/manual differential leukocyte count with complete blood count (CBC) provides the complete hematologic picture of the case, at least from the morphologic standpoint. Blood smear review with or without interpretation serves to ensure that no clinically significant finding is missed, besides providing diagnosis or diagnostic clue(s), particularly if and when interpreted by a physician.

Keywords: Blood smear scan, Blood smear examination, Blood smear review