ASTM, HL7 and LIS2-A2: How Analyzers Talk to Software
The protocols behind analyzer integration — ASTM E1381/E1394, LIS2-A2, HL7 and MLLP — what each does, and what to ask a vendor before you buy.
Every quote for analyzer integration contains an acronym the buyer is not expected to question. It is worth questioning, because the answer determines whether your next analyzer connects in an afternoon or becomes a three-month project.
The two families you will meet
| Standard | What it is | Where you meet it |
|---|---|---|
| ASTM E1381 / E1394 | The older pair: E1381 defines how bytes move over a serial line, E1394 defines the record structure carried on it. | A very large share of installed chemistry, haematology and immunoassay analyzers. |
| LIS2-A2 (with LIS1-A) | The same two standards renamed and maintained by CLSI. LIS2-A2 is E1394; LIS1-A is E1381. | Newer instruments and documentation. If a datasheet says LIS2-A2, it means ASTM. |
| HL7 v2 | A broader healthcare messaging standard — orders, results, admissions — used well beyond the analyzer bench. | Hospital systems, middleware, and instruments that speak HL7 natively. |
| MLLP | Not a message format: the thin wrapper that carries HL7 messages over a TCP connection so the receiver knows where one ends. | Any HL7-over-network link. If someone says "HL7 over TCP", MLLP is what they mean. |
The single most useful thing to know: LIS2-A2 and ASTM E1394 are the same thing under two names. Vendors quoting one and asking about the other has caused more confusion than any genuine incompatibility.
Serial or network
Older instruments present a serial port and expect a cable to a COM port on the lab computer. Newer ones offer Ethernet, and some offer both. Neither is better for correctness; the practical differences are distance, how many instruments one machine can serve, and what happens when someone unplugs something. A serial link is point-to-point and stubbornly reliable. A network link survives being moved across the room.
Unidirectional and bidirectional
A unidirectional link sends results from the instrument to the software. A bidirectional link also sends the worklist the other way, so the analyzer knows which tests to run on which barcode without anyone keying it in. Bidirectional removes a whole class of transcription error and is worth having wherever the instrument supports it — the longer comparison covers the trade-off in detail.
The part nobody quotes for: the field map
Two analyzers can both speak perfect ASTM and still disagree about everything that matters. One calls a test "GLU", another "Glucose", another a numeric code. One reports in mg/dL, another in mmol/L. One sends sex as M/F, another as 1/2. The standard says how to package a message; it does not say what the contents mean.
So every real integration includes a mapping between the instrument’s vocabulary and the laboratory’s catalogue. When that mapping is written into program code, adding an analyzer means a software release. When it is data — a profile naming the vendor, the model, the protocol, the transport and the field and code maps — a new instrument is a new profile, and it can be produced without touching the application.
SamLab takes the second approach: analyzer support is defined by profiles carrying the vendor, model, protocol (HL7, ASTM, LIS2-A2 or a custom parser), transport (serial, TCP or both) and the field and code maps, rather than one hard-coded driver per instrument. Its HL7 side implements MLLP for network links. The integration list lists the instrument families already running in the field, and the honest caveat applies throughout: the exact make and model is confirmed before anyone commits to it.
What to ask a vendor
- Which protocol and transport does my specific model use — and will you confirm that model before I pay?
- Is the link unidirectional or bidirectional on this instrument?
- Who writes the field and code map, and what does it cost when I add an analyzer later?
- Does adding a new analyzer need a software update, or is it configuration?
- What happens to results that arrive while the software is closed or the machine is off?
- Can I see the raw messages when something looks wrong?
The last two separate a real integration from a demo. Instruments run when nobody is watching, and the first question after an odd result is always what the analyzer actually sent.
Frequently asked questions
Is LIS2-A2 different from ASTM?+
No. LIS2-A2 is the CLSI name for what was ASTM E1394, and LIS1-A is what was E1381. A datasheet quoting LIS2-A2 and a vendor quoting ASTM are describing the same protocol.
Do I need HL7 if my analyzers speak ASTM?+
Not for the analyzers themselves. HL7 matters when you also exchange orders and results with a hospital information system or a referral network. Many labs run ASTM at the bench and HL7 outward, and the two do not conflict.
Can any analyzer be connected?+
Most clinical analyzers can, because most speak one of these standards. The realistic answer is still model by model: an instrument can support a protocol on paper and expose it only with an optional interface board or a vendor licence. Confirm your exact make and model before committing.
Keep reading
- Immunoassay Analyzer Integration: What Makes It Different
Immunoassay results are often the clinically decisive ones, and their reference ranges depend on things a chemistry range never does.
- NABL Report Format: Every Field, and Why Each One Is There
A NABL report is not a design problem. It is a list of facts an assessor expects to find, laid out so a clinician can read it quickly.
- LIMS Software in India: What Labs Search vs What They Need
Most Indian labs typing "LIMS" are running a diagnostic lab, and a diagnostic lab wants a LIS. Buying the wrong category is expensive in a specific way.