i) Patients with an abnormal blood count requiring investigation by blood and bone marrow sample.

ii) Patients known to have a blood disorder who are having a bone marrow sample taken as part of the assessment of that disorder.

Control subjects

Patients having elective orthopaedic surgery who have a normal blood count.

i) Age < 18.

Controls

i) Age <18.

ii) On treatment likely to impair bone marrow function

iii) History of having had treatment likely to have impaired bone marrow function