Basophils %
What it measures, and what changes the number.
Basophils % is the share of all white blood cells that are basophils, the least common white cell type, which carries histamine containing granules involved in allergic and inflammatory responses.
It is part of the white cell differential in a complete blood count and is read with the absolute basophil count and the total white blood cell count, since a percentage alone can shift when other cell types rise or fall. The other differential percentages, such as eosinophils and neutrophils, appear on the same report.
The count is made on an EDTA blood sample by an automated analyzer, sometimes checked by manual smear review, and small counts like this differ somewhat between analyzers. Labs may print it as Basòfils or Basófilos %.
Often read alongside: Basophils, White blood cells, Eosinophils %, Neutrophils %, Lymphocytes %