Cell counters, centrifuges including the microhaematocrit, microscopy and staining, and how to lay out a haematology bench so that a routine morning workload moves in one direction without doubling back.
A haematology bench is judged on one thing by the clinicians who use it: whether a complete blood count requested at nine in the morning is reported before the ward round finishes. Everything on the bench either serves that or gets in its way. The equipment list is short and well understood. What goes wrong is the arrangement, and what gets underspecified is the plan for the days the analyser is down.
For most Bangladeshi hospital laboratories the routine is a complete blood count, erythrocyte sedimentation rate, a stained peripheral film on request or on a flagged count, packed cell volume where the count is doubtful or the analyser is unavailable, reticulocytes, and malaria screening by film and by rapid test. Add haemoglobin electrophoresis or high performance liquid chromatography only where the hospital genuinely runs a thalassaemia service, because in Bangladesh that is a real and growing workload rather than a theoretical one, and it needs its own bench and its own trained staff.
Count samples at the peak hour, not the daily total. A laboratory taking outpatient bloods from eight until eleven will see most of the day's tubes arrive inside those three hours, and the analyser has to clear them while the phlebotomy room is still filling racks.
A three part analyser separates leucocytes into granulocytes, lymphocytes and a middle fraction. A five part analyser reports neutrophils, lymphocytes, monocytes, eosinophils and basophils separately. The five part instrument costs more to buy and more to run, and it earns that where the hospital treats haematology or oncology patients, or where eosinophil counts drive clinical decisions often enough to matter.
What neither does is replace the microscope. A haematology service without a working microscopy bench and somebody competent at the eyepieces is not a haematology service, whatever the analyser prints. The analyser flags; a person decides. Budget the microscope, the stain and the technologist's time as part of the analyser purchase rather than as a separate wish for next year.
Ask about reagent packaging as well as price. A pack sized for a high throughput laboratory has an open stability period that a low volume laboratory cannot use up, so you pay for reagent that goes down the drain. On a small workload, smaller packs at a higher unit price are frequently cheaper in practice.
A general laboratory centrifuge does not spin capillary tubes, and a microhaematocrit centrifuge does not do anything else. They are two instruments because the duty is different: packed cell volume needs a high relative centrifugal field for a short time in a rotor built for sealed capillaries. The GEMMY KHT-410 takes twenty four capillary tubes on its rotor, with a timer, a brake and a safety lid lock, and that is the whole job.
Keeping a working microhaematocrit centrifuge and a supply of capillary tubes is the cheapest continuity measure a haematology bench can take. When the analyser is waiting for a part, a manual haemoglobin and a spun packed cell volume keep the wards supplied with a usable number. Laboratories that dispose of the manual capability the week the analyser arrives regret it within the year.
For everything else, a benchtop universal centrifuge with interchangeable rotors covers serum separation, urine deposits and washing steps. Two points on specification: choose the rotor by the tube you actually use rather than by the top speed on the brochure, and insist on a lid interlock and imbalance detection. A unit like the GEMMY PLC-012 takes different rotors on the same drive with a hexagon wrench, which is the right arrangement for a bench handling several tube types.
The film bench is where the quality of a haematology service becomes visible, and it is usually the worst equipped part of the room.
Set the bench up as a line: sample reception and checking, mixing, analyser, film spreading, staining, microscopy, then reporting. Work should move along it in one direction and never come back. Every doubling back is a handling step, and every handling step is where a tube gets picked up out of order.
Where the laboratory also runs coagulation, keep it physically separate. Citrate tubes need their own centrifuge settings and their own timing discipline, and a coagulation sample sitting in a haematology rack while somebody finishes a batch of counts is a wasted sample and a repeat venepuncture.
Reagent supply comes first. An analyser with no lyse or diluent is furniture, and the interruption is almost never the analyser's fault. Hold a defined minimum stock and reorder against measured consumption rather than against a feeling.
Then the sample probe and the aspiration path, which block, bend or leak, and which are usually a scheduled clean that was skipped rather than a failure. Then the printer, which in a public hospital fails from paper and dust more often than from electronics. Then the centrifuge lid latch, from being slammed. Then, quietly and over years, the microscope, from fungus, from oil left on the objective overnight, and from being carried by the stage.
Only two of those are engineering problems. The rest are handling and stock, which means the standing operating procedure and the store card do more for uptime on a haematology bench than any specification decision made at tender.