Overview
Automation refers to machines with intelligence and adaptability that reduce workload and the need for nonstop human supervision. In the clinical laboratory, automation touches nearly every step of the analytical process — from patient identification and sample collection to final reporting.
Automated analyzers (auto analyzers) have transformed laboratory medicine by reducing human error, improving reproducibility, saving time, and enabling far higher testing throughput than manual methods ever could — while introducing new considerations around cost, maintenance, and training.
Learning Objectives
After this lesson you will be able to…- Define automation and list its uses in the clinical laboratory.
- Discuss automation at each step of the analytical process.
- Describe different types of auto analyzers (open vs closed, modular vs integrated).
- Differentiate continuous flow processing from discrete processing.
- Enlist the advantages and disadvantages of laboratory automation.
Clinical Story
Why This MattersA busy hospital lab processes hundreds of samples daily for a nephrotic syndrome patient's renal panel — total protein, albumin, and creatinine. Without automation, a technician would manually pipette and time each reaction for every sample. With a random access auto analyzer, results for dozens of patients are generated simultaneously with minimal manual handling, reducing turnaround time and the risk of transcription errors — a direct result of understanding how these instruments work.
Core Concepts
The full laboratory process includes: identifying the patient, getting the correct sample, identifying/labeling the sample, delivering it under proper storage and within time, preparing the sample, sample loading/aspirating, analysis, reporting, and entering into the register. Automation can be applied at multiple points, including sample collection (glucometers, vacutainers, robotic systems), sample identification (bar coding), sample delivery (pneumatic tube systems, conveyer belts, mobile robots), and sample preparation (automated sample processors).
In an open system, the operator can purchase reagents from any company, reducing cost per test; a modular design increases flexibility. In a closed system, reagents must come from one manufacturer in proprietary formats, raising cost but allowing higher automation with fewer trained staff. A modular system is built of separately replaceable parts (like a modular kitchen) so a fault in one part doesn't disrupt the whole machine (e.g., Roche Modular P). An integrated system merges functionality into one solution with improved communication and data exchange, but service/maintenance requires company engineers.
Continuous flow analyzers (CFA) inject the sample into a continuously flowing carrier solution through tubing and mixing coils, using air bubbles to prevent carry-over between samples. This is time-tested for batch analysis but wastes reagents even when idle. Discrete processing gives each sample and analysis its own separate cup/cuvette, eliminating carry-over entirely and saving reagent cost — the basis of modern centrifugal analyzers (fast batch reading, one test at a time) and random access analyzers (most versatile — multiple tests on multiple samples simultaneously).
Laboratory Principle
In continuous flow processing, the sample and standard travel through identical tubing length and conditions, removing the systematic difference between the two — so the difference in absorbance readings between a test-tube and standard directly gives the analyte concentration. In discrete processing, exact volumes of sample and reagent are aspirated and mixed independently for each analysis, so results are unaffected by any other sample being run concurrently, eliminating carry-over completely.
Equipment Required
Reagents & Materials
| Reagent / Material | Concentration / Grade | Purpose | Storage |
|---|---|---|---|
| Assay-specific reagent kits | Open system (any brand) or closed system (proprietary) | Colorimetric/enzymatic reactions run by the auto analyzer | Per manufacturer instructions, usually 2–8°C |
| Distilled water | Type II/III laboratory grade | Keeps probe/tubing free of clogs between samples in CFA | Room temperature |
| Anticoagulants (in vacutainers) | EDTA, heparin, citrate — colour-coded | Prevents clotting for plasma/whole blood analysis | Room temperature, dry |
Step-by-Step Procedure
The laboratory information system generates a unique hospital number, which is bar coded onto the sample tube and, where used, the patient's wrist band.
Blood is drawn using a vacutainer, where negative pressure draws blood into the tube without the phlebotomist needing to pull a syringe plunger.
The sample is transported to the laboratory via human pick-up, conveyer belt, pneumatic tube system, or mobile robot, depending on the lab's automation level.
Automated sample processors sort, uncap, and load samples into the auto analyzer, which aspirates the exact volume needed for each requested test.
The auto analyzer runs the assay (continuous flow or discrete), and results are sent electronically to the hospital information system for review, approval, and printout.
Flow Diagram
Quality Control
Run normal and abnormal internal controls through the auto analyzer at the start of each shift, ensure the probe/tubing is free of clogs (kept in distilled water when idle in CFA systems), and monitor for instrument alarms indicating malfunction.
Auto analyzers should be enrolled in external proficiency testing programs specific to each assay to confirm ongoing accuracy against peer laboratories using similar or different platforms.
Reference Values
Key Concepts⚠️ Reference ranges may vary between laboratories. Always apply your laboratory's established reference intervals.
Clinical Interpretation
| Finding | Possible Significance | Action / Follow-up |
|---|---|---|
| Repeated instrument flags/alarms | Probe blockage, reagent depletion, or calibration drift | Halt run, troubleshoot, recalibrate before resuming |
| Consistent result agreement with QC | Analyzer functioning within acceptable limits | Proceed with routine patient testing |
| Turnaround time significantly increased | Sample delivery delay, workflow bottleneck, or system fault | Review workflow, check pneumatic/conveyor systems |
Common Errors & How to Avoid Them
Cause: Precipitation or clots forming in the probe/tubing when idle.
Prevention: Always dip the probe in distilled water when no sample is being processed to prevent blockage or precipitation.
Cause: Manual transcription error in labeling samples.
Prevention: Use computer-generated bar coding for both patient and sample identification to eliminate transcriptional error.
Cause: Overlooking costs of trained personnel, system upgrades, and ongoing maintenance.
Prevention: Budget for the full lifecycle cost of automation, not just purchase price.
Laboratory Tips from the Bench
Even in a fully automated lab, always visually check for hemolysis, lipemia, or clots before loading a sample — automation cannot always detect pre-analytical sample quality issues.
When choosing between open and closed reagent systems, weigh reagent cost savings against the higher automation and lower staffing needs of closed systems.
"CFA flows, Discrete grows separate" — Continuous Flow Analyzers use one flowing stream with air bubble separation, while Discrete analyzers give every reaction its own separate cup.
Important Notes
Beyond the purchase price, automation carries hidden costs including trained personnel, supply and maintenance contracts, and periodic system upgrading — labs must budget for these to sustain automated workflows.
Random access analyzers can run multiple different tests on multiple different samples simultaneously by giving appropriate commands to the computer software, making them the most flexible discrete processing option.
Interactive Quiz
Test Your KnowledgeFlashcards
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Clinical Case Study
Apply Your KnowledgeThe lab processes over 800 biochemistry samples daily. Frequent manual transcription errors and long turnaround times have led to complaints from clinicians about delayed patient reports.
This is a classic scenario favoring investment in bar coding for sample identification and a random access discrete auto analyzer, which together reduce transcriptional error, save reagent cost, and dramatically improve turnaround time.
- →Bar coding significantly reduces manual transcription errors in patient/sample identification.
- →Random access analyzers are best suited to high-volume, high-variety test menus.
- →Automation investment must also account for hidden costs like staff training and maintenance.
Frequently Asked Questions
Even when no test is being done, reagents must be drawn to maintain the continuous flow, adding to cost per test. CFA systems also require more frequent maintenance and occupy large physical space.
Closed systems offer a high degree of automation and can be managed by just one or two well-trained technical assistants, which can offset the higher reagent cost through reduced staffing needs and improved reliability.
No. Due to hidden costs and the need for trained personnel at each stage, many laboratories restrict automation to the laboratory analysis level itself, using the auto analyzer as the primary automated component while other steps remain partly manual.
Quick Revision
10-Minute ReviewKey Takeaways
- Analysis in the lab can be automated from patient identification through to report delivery.
- Hidden costs and trained personnel requirements often restrict full automation to the analysis level.
- Modern auto analyzers mostly run on the discrete processing principle, avoiding carry-over effect.
- Random access analyzers are the most versatile, allowing multiple tests at any time.
- Integrated systems improve efficiency but increase maintenance tasks and cost per test.
Competency Checklist
Track Your MasteryReferences
- NIOS Biochemistry Module — Lesson 25: Automation in Clinical Laboratory.
- Burtis CA, Ashwood ER, Bruns DE. Tietz Textbook of Clinical Chemistry.
- CLSI Guidelines on Laboratory Automation.