General blood tests and leukocyte differential count are very useful in diagnosing, treating and managing patient’s diseases. This study was conducted to reduce errors caused by the manual method as much as possible by using an automated hematology analyzer (Sysmex K-4500), and to alleviate work burden of the laboratory. The T1 and T2 values calculated from leukocyte differential count that was obtained from the automated hematology analyzer Sysmex K-4500, and the results measured from the manual method were compared and analyzed by using the blood samples of 400 patients who were commissioned in the diagnostic laboratory of the hospital with 120 beds. Upon the results of the study, T1 and T2 obtained from lymphocyte differential count of the automated hematology analyzer Sysmex K-4500 demonstrated high correlation compared to manual method, and the analysis of monocyte, eosinophil, basophil and band cell obtained from T1, T2 and manual method enabled percentile calculation, even though it was difficult to predict the exact monocyte, eosinophil, basophil and band cell. Therefore, it is regarded that the optimal patient results can be reported if manual method observation is selectively combined while referring to T1 and T2 obtained from lymphocyte differential count of the automated hematology analyzer Sysmex K-4500.

Abstract
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Collection of Samples
    2. Manual method using microscopic analysis
    3. Analysis Using the K-4500
    4. Statistical Analysis
Ⅲ. RESULTS
    1. Comparison of leukocyte differential count using automated hematology analyzer and manual method in normal and abnormal blood samples
    2. Comparison of automated hematology analyzer results from T1 and T2 values in normal and abnormal blood samples
    3. Frequency of T1 and T2 in normal and abnormal blood samples
    4. Correlation of leukocyte count between automated hematology analyzer and manual method in normal and abnormal blood samples
    5. Analysis result of monocyte, eosinophil, basophil and band cell by comparing the correlation of mixed cell percentile value and graph result in the automated hematology analyzer in normal blood samples
    6. Analysis result of monocyte, eosinophil, basophil and band cell by comparing the correlation of mixed cell percentile value and graph result in the automated hematology analyzer in abnormal blood samples
Ⅳ. DISCUSSION
REFERENCES

• 오은주(단국대학교대학원 의학레이져 협동과정) | Eun Ju Oh (Department of Medical Laser Cooperative Curriculum, Dankook University Graduate School of Medicine)
• 이영기(단국대학교 보건복지대학 임상병리학과) | Young Ki Lee (Department of Biomedical Laboratory Science, Dankook University College of Health Sciences)
• 김가연(단국대학교 보건복지대학 치위생학과) | Ga-Yeon Kim (Department of Dental Hygiene, Dankook University College of Health Sciences) Correspondence