Erythropoietin (EPO) exhibits a range of isoelectric points (pI) due to its glycosylation. The pI of erythropoietin is not a single value, but rather a range. According to the provided reference, urinary samples of erythropoietin show a heterogeneous composition of more than 10 isoforms within a pI range of 3.7-4.7.
In summary, erythropoietin does not have a single pI value, but rather exists as a mixture of isoforms with pI values ranging from 3.7 to 4.7. This range is due to variations in glycosylation patterns.
