Skip to main content
hematologyanalyser.myby AA Alive Sdn Bhd
ENBM

Also called: Blood smear, Peripheral blood film, Blood film review

Peripheral Blood Smear: When and How to Review a Blood Film

An analyser counts cells; a trained eye recognises them. When a film is needed, how to make and stain a good one, and the equipment that supports it.

Call 011-2879 9609

Last updated:

When the analyser result needs a film

Every lab should write down its own criteria for sending a sample to film review. The International Society for Laboratory Hematology (ISLH) published consensus review criteria — the widely cited “41 rules” — that many labs adapt to their analyser and patients.

  • Analyser flags such as blasts, immature granulocytes, atypical lymphocytes, nucleated red cells or platelet clumps.
  • Results outside your lab’s review limits, especially a first-time abnormal result.
  • A large unexplained change from the patient’s previous result (a failed delta check).
  • A 3-part analyser result where the mid-cell group is raised and the cause matters.
  • A clinical request — suspected malaria, haemolysis or a blood disorder.

Read next Analyser flags and histograms

Making a good wedge smear

  • Make films promptly from a well-mixed EDTA sample — storage artefacts develop as the sample ages.
  • Place a small drop near the frosted end of a clean slide and label the frosted end in pencil.
  • Hold a spreader slide at about 30–45°, draw it back into the drop, let the blood spread along its edge, then push forward in one smooth movement.
  • Aim for a film covering most of the slide with a thin, feathered tail. Adjust the angle and speed for anaemic or very concentrated samples.
  • Air-dry quickly and fix in methanol before staining, as your stain method specifies.

Staining: the Romanowsky family

StainWhere you will see itNotes
LeishmanWidely used in Malaysian and UK laboratoriesMethanol-based; fixes and stains in one solution before buffer is added
Wright and Wright-GiemsaCommon with automated stainersSimilar results to Leishman
May-Grünwald-GiemsaCommon in European laboratoriesTwo-step stain with crisp nuclear detail
GiemsaThe standard stain for malaria parasitesUsed on thick and thin films; buffer pH matters — malaria microscopy commonly uses pH 7.2

What a film shows that the analyser cannot

Abnormal white cells

Blasts, atypical lymphocytes, left shift and toxic changes, which an analyser can only flag as suspicious.

Red-cell shape

Fragments, spherocytes, target cells and other shapes that point towards haemolysis, thalassaemia or other conditions.

Platelet clumps

Confirms a falsely low platelet count from clumping before it changes management.

Platelet clumping and EDTA

Parasites

Malaria parasites and other blood parasites. In Malaysia, zoonotic Plasmodium knowlesi causes most locally acquired malaria, and malaria is a notifiable disease.

Equipment, from clinic to hospital lab

  • A good binocular microscope with 10×, 40× and 100× oil-immersion objectives and properly set-up illumination.
  • A staining station or rack, timers, buffer and filtered stain — or a small automated stainer.
  • In high-volume labs, an automated slide maker and stainer connected to the haematology analyser, which makes films only for samples that meet the review rules.
  • Digital morphology analysers, which photograph and pre-classify cells for a trained reviewer to confirm. They speed review; they do not replace the morphologist.

Read next Hospital lab automation

Competence and quality

  • Only trained staff should report a film, with a clear route to a pathologist for anything abnormal.
  • Keep a reference atlas and review difficult films together.
  • Join a morphology EQA scheme so your reading is compared with other labs.
  • Record which samples went to film review and why, and check your criteria still fit your patients.

Read next EQA and accreditation

Related guides

CBC Machine: Complete Blood Count Analyzers and Their ParametersA parameter-by-parameter guide to what a CBC analyzer reports, how to read its histograms and flags, and when it needs a human eye.Haematology Analyser Quality Control and CalibrationThe routine that keeps every FBC result trustworthy — from the morning control run to external quality assessment and accreditation.5-Part Haematology Analyser: Technology, Parameters and UpkeepHow a 5-part analyser separates the five white-cell types, what it adds to the report, and what it asks of your lab every day.

Hematology Analyser supply near you

Delivery, installation and training across Malaysia from Batu Caves, Kota Kinabalu and Kuching.

See all 28 locations

Frequently asked questions

Does every FBC need a blood film?
No. Most normal results are reported from the analyser alone. Films are made for samples that meet your lab’s review criteria, such as flags, first-time abnormal results or a clinical request.
Which stain is used for blood films in Malaysia?
Leishman stain is widely used for routine films, and Giemsa is the standard for malaria parasites. Wright-based stains are common with automated stainers.
Can a 5-part analyser replace the blood film?
It reduces the number of films needed, but cannot identify every abnormal cell or parasite. Flagged samples still need a film reviewed by trained staff.
Should a GP clinic make its own blood films?
Only if staff are trained and a reviewer is available. Many clinics send flagged samples to a laboratory for film review instead.

Get a written quotation

Tell us your clinic or lab type, daily workload and location. We match suitable models and send a written quotation with delivery, installation and training spelled out.