Related Experiment Video
Updated: Mar 18, 2026
Colorimetric Analysis of Alkaline Phosphatase Activity in S. aureus Biofilm
Published on: April 12, 2019
Semi-Automatic Rating Method for Neutrophil Alkaline Phosphatase Activity
Kanae Sugano1, Kotomi Hashi2, Misaki Goto3
1Department of Clinical Laboratory, NTT East Japan Sapporo Hospital, Sapporo, Japan.
Background:
The neutrophil alkaline phosphatase (NAP) score is a valuable test for the diagnosis of myeloproliferative neoplasms, but it has still manually rated. Therefore, we developed a semi-automatic rating method using Photoshop® and Image-J, called NAP-PS-IJ.
Methods:
Neutrophil alkaline phosphatase staining was conducted with Tomonaga's method to films of peripheral blood taken from three healthy volunteers. At least 30 neutrophils with NAP scores from 0 to 5+ were observed and taken their images. From which the outer part of neutrophil was removed away with Image-J. These were binarized with two different procedures (P1 and P2) using Photoshop® . NAP-positive area (NAP-PA) and granule (NAP-PGC) were measured and counted with Image-J.
Results:
The NAP-PA in images binarized with P1 significantly (P < 0.05) differed between images with NAP scores from 0 to 3+ (group 1) and those from 4+ to 5+ (group 2). The original images in group 1 were binarized with P2. NAP-PGC of them significantly (P < 0.05) differed among all four NAP score groups. The mean NAP-PGC with NAP-PS-IJ indicated a good correlation (r = 0.92, P < 0.001) to results by human examiners.
Conclusions:
The sensitivity and specificity of NAP-PS-IJ were 60% and 92%, which might be considered as a prototypic method for the full-automatic rating NAP score.
