Sickle Solubility Test

Test Alias / Common Abbreviations

Sickle cell screen;  Sickledex; Sickle Dex

 

Department


Haematology


Test Purpose  

To detect the presence of sickling haemoglobins.


May be used as screening test prior to urgent surgery or as a confirmatory test as part of Haemoglobinopathy Screening.


NB. Positive results do NOT distinguish between sickle cell disease and sickle cell carriers/trait


Important Requesting Instructions

 

Discuss with laboratory if required prior to urgent surgery.

Sample Collection Instructions

Venous whole blood.


For further information see here.

Sample Transport & Stability Information


Packaging must be compliant with Dangerous Good Safety Advisor (DGSA) requirements click here for more information.

Samples should be delivered to the laboratory as soon as possible to ensure processing within 24 hours post collection. When same day delivery is not possible, refrigerate sample at 2-8 ⁰C.

 

Sample Type, Container & Volume

1 X EDTA (Purple)

 

 

 

Minimum 20ul whole blood
Additional volume required for associated FBC and Haemoglobinopathy Screening.

 

Turnaround Time

Analysed at Royal Stoke University Hospital only


2-3 hours if required prior to urgent surgery. 


See Haemoglobinopathy Screening for turnaround time of confirmatory testing.

Positive/Negative

Positive results in previously undiagnosed patients will be phoned to the requesting source.

False positive results may occur with erythrocytosis, hyperglobulinaemia, extreme leucocytosis and hyperlipidaemia.


False negative results may occur in infants <6 months old, patients with severe anaemia and post transfusion.


The test detects sickling haemoglobins and is not specific to HbS; positive results can occur with other rare sickling haemoglobins.  


Limit of detection is stated to be 15% of total haemoglobin.

NICE NG45 (2016) recommends the following regarding Routine preoperative tests for elective surgery


•    Do not routinely offer testing for sickle cell disease or sickle cell trait before surgery.
•    Ask the person having surgery if they or any member of their family have sickle cell disease.
•    If the person is known to have sickle cell disease and has their disease managed by a specialist sickle cell service, liaise with this team before surgery.
Positive results do not distinguish between sickle cell carriers and sickle cell disease.
All sickle cell solubility results will be followed up by confirmatory testing.

 Please see Haemoglobinopathy Screening for further information.


Analysed at Royal Stoke University Hospital, requests can sent to County hospital for onward transport to Royal Stoke.

Updated On: 21.05.2025