Sir,I read the recent publication on electrolytes assessed by point-of-care testing (POCT) in sepsis with great interest.[1] Chacko et al. concluded, “Clinicians should be aware of the difference between whole blood and serum electrolytes, particularly when urgent samples are tested at point of care and routine follow-up electrolytes are sent to the central laboratory” and “A correction factor needs to be determined at each center”.[1] Indeed, the result in this work can be expected. Two samples that are processed at different time intervals can usually have different laboratory data. To compare between two analyzers, the data on the quality control and the reference range of the two systems have to be presented. These are the basic things in laboratory medicine that can result in difference of data from two analyzers. Finally, I would like to make a comment on the suggestion to find the correction factor. This needs a clarification as such correction factor might be usable only if the same kinds of specimens are used. In case venous blood specimen is used for analysis in central laboratory and arterial blood is used for analysis by POCT tool, it should be corrected.