Determination of Calreticulin (CALR) mutation status based on peripheral blood immunohistochemistry and flow cytometry.

This study is testing two new blood testing methods — flow cytometry and immunohistochemistry — to detect a genetic mutation called the Calreticulin (CALR) mutation, which is found in certain blood disorders called myeloproliferative disorders. Currently, this mutation is detected by a technique that takes more time and resources. If these new methods are accurate, testing for CALR mutations could become faster, cheaper, and less invasive. Participants simply provide an extra 10 mL of blood during their routine blood tests. You may be eligible if: - You are 18 years or older - You have a known myeloproliferative disorder - You have previously had molecular testing for JAK2, MPL, or CALR mutations - You are an active patient of the St Vincent's Hospital Haematology Service with regular blood tests You may NOT be eligible if: - You have a psychological illness or condition that would prevent you from understanding the study or giving consent Talk to your doctor about whether this trial might be right for you.