text: Basophils are a group of white blood cells which are normally in charge of producing immunoglobulins related to allergic reactions. Their numbers are the least among all white cells (about 100 to 200 per cubic mm of blood). SOmetimes blood tests aren't sensitive enough to detect circulating levels of basophils (they may be residing in certain other tissues in your body), and thus the absolute basophil count may turn out as zero. So don't be too worried about it; if the other indices in your blood work are normal, there shouldn't be a problem.