Blood Film

Testing Laboratories

Department

Haematology

Delphic Registration Code (Alpha Code)

FILM, FBC

Test Code (Numeric Code)

1101

Laboratory Handling

Sample Stability

The peripheral blood film smear should ideally be prepared within 4 hours of collection. The blood film can be made up to 24 hours after collection if the FBC is stored at 4 degrees C, but artefactual changes may occur.

Associated Tests

• Full blood count (FBC)

Synonyms

White Cell Differential (Blood Film)
Eosinophils
Differential (White Cell)

Turnaround Time

6 hours

Proposed 6 hours by Scientist, 48 hours by Haematologist

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

3

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Minimum Sample Volume (ml)

0.5

The full blood count results pass through a series of algorithms that take into account previous results and analyser flagging. A blood film is made if the results are significantly abnormal, flagged by the analyser or have changed significantly from previous results. Films are examined on all children under 180 days old and films on dialysis patients every 3 months unless there is a significant change.

At Middlemore all blood films are analysed through CellaVision. This is an automated microscope system that takes high resolution images of the blood cells and then identifies the various cell types using a neural network. These images are sent to monitors where they are verified or amended by Haematology staff. Some blood films may still be examined by microscope.

The blood film examination includes a comment on red and/or white cell morphology and a scanned platelet estimate. In most cases the automated differential will be reported from the analyser but if there is a significant left shift or an abnormal white cell population then a 100 cell differential may come from CellaVision or be counted using the microscope.

Contact Information