Most clinical laboratories perform the leukocyte differential count by eye manual methods. But manual count has received much criticism because it's poor precision, low sensitivity, intensive labor and inherent analytic variabilities.
Recently developed Coulter counter medel Stack-S (STKS) utilizied principle of flow cytometry as well as electrical impedance and excutes five-part differential count based on volume, conductivity, light scartting (VCS principles).
An evaluation of Blood cell count on the STKS was carried in 540 specimens by means of comaprision betweens the STKS and STKR hematologic parameters and 485 specimens by means comaprision between the STKS and manual count method of 100 cell
diffential
count, and analysis of flags.
@ES The results are as follows,
@EN 1. Precision (within run, between run, day to day precision) were acceptable CV below 3.0% over the entire parameters except monocyte, eosinophil, and basophil
2. We compared the performance in the 9 parameters of Coulter(r) STKS model with those of Coulter(r) STKR model and good correlation (r= 0.96 - 0.99) over all.
3. WBC differential count on STKS was compared with manual count. The correlation was good in neutrophil, lymphocyte, and moderate in monocyte, Eosinophils. The mean of monocyte and basophil were estimated higher in STKS than in manual count.
4. Among 485 specimens evaluated for flagging, total flag was 286 cases (59%) and it consisted of suspect flag only (78 cases), definitive flag (116 cases), and suspect and definitive flags (92 cases).
In summary, we thought STKS could replace the routine manual differential count particularly if it was supplemented with a review of stained blood smear and confirmed peripheral morphology when alarmed suspected flags.
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