Used as a screening test to detect structual defects in the red cell membrane associated with Hereditary Spherocytosis.
Refer to the following two documents:
Screening Tests for Hereditary Spherocytosis
Guidelines for Diagnosis of Hereditary Spherocytosis
Haematology - Special Tests
Pre-Testing Requirements- please follow the following steps (or the attached flowchart):
1. EMA Binding test request available M-W only, before 1 pm.
2. Requestor to contact Haematology lab to coordinate when test can be done .
3. Special Haeme Lab Staff to contact Waikato Hospital regarding timing of test.
4. Once timing is confirmed, SMO requesting the EMA-binding test to contact blood test centre in outpatients building to ask phlebotomists
to collect control samples as per standard protocol. SMO to remind phlebotomist to collect 5 normal control samples (EDTA) within 1 hour
of patient sample being taken.
5. Notes for the phlebotomist:
• Collect 1 EDTA sample from patient, keep chilled.
• Collect 1 EDTA sample each from 5 ‘controls’.
• Keep all samples chilled right after collection.
• Controls will not have a specific blood form and do not need to be labelled with any patient identifying features. Just label them as
• Patients attending for blood tests at the same time as patient can act as controls.
• Only verbal consent is needed for controls’ collection.
• Example wording for discussion with patient:
‘We have a patient who needs to have a specialist blood test done. This also requires some additional samples from control subjects
to be taken at the same time. Given that we are already taking a blood sample from you, would you mind if we took an extra tube
of blood? Your details will not be written on the blood tube so this sample will be anonymous. Thank you.’
• Collate patient and control samples and send to lab in chilly bin. Label bin as ‘Please deliver to Specialist Haematology’
6. Special Haematology Staff to organize dispatch of samples to Waikato laboratory.
Results of the EMA binding test should be interpreted in conjunction with clinical information, red cell indices and blood film findings.
A mean channel fluorescence below the cutoff value of 45.5 is consistent with a diagnosis of Hereditary Spherocytosis.
Flow cytometry method which quantitates the fluorescence intensity as mean channel fluorescence (MCF) of intact red cells after incubation with eosin-5'-maleimide (EMA)
$254.43 (Exclusive of GST)
Referred to Haematology laboratory, Waikato Hospital
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