{"id":"basophils-percent","name":"Basophils (Percent)","shortName":"Basophils (%)","aliases":["BASOPHILS","Basophils %","Basos","Baso %","Baso%","Basophil Percent","Basófilos %","Basophile %","Basophils, Percent","Basophil %","Basophils (%)","Basophils Percent","% Basophils","Basophils Relative","Basophils Relative Percent","Baso (%)","Basophils/100 leukocytes","Basophils/Leukocytes","BASO PCT"],"abbreviations":["BASO%"],"loinc":[{"code":"706-2","primary":true},{"code":"707-0","primary":false},{"code":"30180-4","primary":false},{"code":"71680-3","primary":false}],"specimen":"whole-blood","units":[{"ucum":"%","display":"%"},{"ucum":"1","display":"fraction (0–1)"}],"referenceRanges":[{"population":"Adults","low":0.3,"high":1.4,"unit":"%","unitDisplay":"%","note":"ARUP interval for all ages. Labcorp does not set a range for the percent ('Not Estab.' on its reports) and Mayo reports absolute counts only. A classic textbook table gives 0.6 to 1.8, and MedlinePlus lists about 0.5 to 1. Automated and microscope basophil counts can agree poorly. A low or zero percent is common and seldom meaningful on its own. Basophilia is usually judged by the absolute count, not the percent.","sources":[{"title":"CBC with Platelet Count and Automated Differential (test 0040003), hotline effective March 1, 2021: reference intervals","url":"https://ltd.aruplab.com/api/ltd/hotline/0040003/44232","publisher":"ARUP Laboratories","year":2021},{"title":"Normal Values for Leukocyte Concentration in Blood (Table 63-1)","url":"https://download.skyscape.com/download/ota/lonestar/76CD77F7-898A-4928-AE45-A3D54D0FF0F0/harrisons.ed19/content/HTML/c/tu13.htm","publisher":"Harrison's Principles of Internal Medicine, 19th edition (McGraw-Hill)","year":2015},{"title":"Blood differential test","url":"https://medlineplus.gov/ency/article/003657.htm","publisher":"MedlinePlus Medical Encyclopedia (National Library of Medicine)","year":2025},{"title":"Sample patient report, test 005013 (CBC with Diff, Platelet, NLR)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/005013.pdf","publisher":"Labcorp"},{"title":"Basophilia","url":"https://www.ncbi.nlm.nih.gov/books/NBK535365/","publisher":"StatPearls (NCBI Bookshelf)","year":2024},{"title":"Blood basophil numbers in chronic ordinary urticaria and healthy controls: diurnal variation, influence of loratadine and prednisolone and relationship to disease activity","url":"https://pubmed.ncbi.nlm.nih.gov/12614448/","publisher":"Clinical and Experimental Allergy","year":2003}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"The share of your white blood cells that are basophils, the rarest white cell type, which takes part in allergic reactions.","url":"https://bloodtesttracker.com/markers/basophils-percent","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}