How to choose the best lab for sterility testing: which labs run the 14-day USP <71> test

How to choose the best lab for sterility testing

Start with the method, then shortlist labs. On price lists, “sterility” can mean a 14-day culture, a microbial count or a DNA screen, and only the first is the pharmacopoeial sterility test, USP <71>. ICH Q4B Annex 8 accepts USP <71>, Ph. Eur. 2.6.1 and the Japanese Pharmacopoeia’s 4.06 as interchangeable, subject to stated conditions. A lab that runs it cultures the tested units in two media for at least 14 days and reports whether anything grew.

Ask every lab on your shortlist five questions before you send vials:

Ask the lab	A clear answer	Why it matters
Which method?	USP <71> or Ph. Eur. 2.6.1, by membrane filtration or direct inoculation	Counts and DNA screens answer other questions
How long?	At least 14 days of incubation	A two- to five-day result comes from a different method
How many vials?	A stated number of unopened units	The result covers only the units tested
Which controls?	Method suitability and negative controls	A sample that stops growth can hide contamination
Who runs it?	In-house, or a subcontractor named on the report	You need to know whose method you are buying

Then ask for an example sterility report. If the example prints only “Pass”, your report will too.

What a USP <71> sterility test involves

The FDA’s Pharmaceutical Microbiology Manual, written for its regulatory laboratories, adds working detail to USP <71>:

• Two techniques. Membrane filtration passes the sample through a filter and cultures the filter. Direct inoculation puts the sample straight into the media; the manual uses it for solids and for liquids that cannot be filtered.
• Two media. Fluid thioglycollate medium at 30 to 35 °C and soybean-casein digest medium at 20 to 25 °C.
• At least 14 days. The media are watched for growth for not less than 14 days.
• Method suitability. A product can stop microbes from growing. A suitability test shows the method still detects them in that product. If it fails, a negative result is invalid.
• Cloudy media. If the sample itself clouds the broth, a portion moves to fresh medium on day 14 and incubates for at least 4 more days.
• Growth. If microbes grow, the product is considered non-sterile, pending an investigation.

The number of units depends on the batch. TrustPointe’s test page summarises the USP <71> table: under 100 vials in the batch, 10% or four vials, whichever is greater; 100 to 500 vials, ten; over 500, twenty. If you send two vials, the result covers only those two. Our explainer on sterility testing for peptides goes through each step.

Which labs list the 14-day USP <71> test

These labs name USP <71> on their own pages (checked September 2026).

Lab	What it lists	Time it publishes	Sample it asks for
Vanguard Laboratory	Sterility (USP 71), an option on every package	14-day testing period	One extra vial
Krause Analytical	“Sterility, 14 Day - USP 71” add-on; also part of its bacteriostatic water package	14 days	Not published
TrustPointe Analytics	USP <71> sterility test; USP <71> testing of sterile vials and pens; organism identification after a failure	14 to 21 days for incubation and analysis	4 to 20 unopened vials by batch size, composited
Accumark Labs	Sterility USP (USP <71>), sold separately from its PCR screen	14 days	A dedicated vial
Bioviridian	Sterility (USP <71>) by membrane filtration or direct inoculation	Not stated for sterility	Two vials
Chromate	Membrane filtration and incubation per USP <71>, for aerobic and anaerobic microbes and yeast; a Chromate report we read cited USP <1223>, the chapter on alternative methods	Not stated	Extra vials beyond the HPLC vial
HK Analytical	Sterility (USP <71>, 14 days)	14 days	Its own unopened vials

Each of these labs does something a buyer can use. TrustPointe says it transfers samples through a closed system in an ISO Class 5 laminar-flow hood without opening the vials, and it can identify the main organism if a sample fails (by MALDI-TOF). Accumark names its PCR screen and its USP <71> test separately, so a buyer can see which one is being ordered. Bioviridian states both compendial techniques. Krause adds sterility to its bacteriostatic water package. Vanguard keeps bioburden (USP 61) in its Gold package apart from the USP <71> option.

MZ Biolabs’ new-services page says sterility by USP <71> methods would be available in early 2025. We found no later update, so ask the lab before you order.

Tests sold as “sterility” that are not USP <71>

Lab	Name on its site	What the method does	Time it publishes
Janoshik	Sterility testing (TAMC+TYMC)	Counts aerobic microbes, yeasts and moulds; pass or fail	14 days
PharmLabs	Sterility & Microbial Screening (TAMC & TYMC)	Counts aerobic microbes, yeasts and moulds	3 to 5 business days
Freedom Diagnostics	Sterility (PCR)	Screens for microbial contamination by PCR	Not stated for this test
ILS Laboratories	Rapid Sterility Screen	DNA microarray for a panel of microbes	Not stated for this test
Accumark Labs	Rapid Sterility Screening (PCR)	DNA-based detection	Not stated for this test

TAMC and TYMC are the total aerobic microbial count and the total yeast and mould count. They come from USP <61>, the microbial enumeration test for products that are not sterile. A count says how many microbes grew from a measured portion. USP <71> asks whether anything grows at all from the units tested. PCR and microarray tests look for microbial genetic material instead of growing live microbes, so they report in days. Freedom, ILS and Accumark describe these as screens, and Accumark says its screen avoids “the 14-day compendial wait”.

Each can be a sensible check if you know what it is. Janoshik’s count runs for 14 days, and its test name says what is measured. LiquiLabs sells the same kind of count as bioburden (USP <61>, Ph. Eur. 2.6.12) and lists no sterility test. Our guide to bioburden vs sterility explains what a count can and cannot show.

Labs that list sterility without naming a method

• BTLabs lists sterility testing under microbiology. The page names no method or incubation time.
• Horizon Analytical includes sterility in its Full QC panel, with 25 days published for the panel. Its terms say sterility is currently performed by SD PharmLabs unless the order names another provider, and that the order or report identifies work done outside. Ask which method that lab runs for your samples.
• MDx BioAnalytical says on its home page that it offers sterility and endotoxin testing. Its services page lists bioburden, TAMC, TYMC and tests for specified organisms, and names no USP <71> test.

Several labs in our research list no sterility test at all; the 19-lab comparison marks them. Finnrick lists a sterility option and says availability depends on the compound and the lab selected, so ask which lab and which method before you add it.

What our review of public reports found

In September 2026 we read public reports from 25 labs. None showed a 14-day USP <71> result together with the number of units tested. One lab’s reports named USP <71> without the unit count. Where other reports used the word “sterility”, it meant a microbial count, a PCR screen, a two-day culture or a reference to a different USP chapter. This does not show that the labs listing USP <71> do not run it; their sterility reports were not in the public record we found. It does mean you should see an example report before you pay.

Ordering a sterility test that answers your question

• Match the test to the question. A finished vial sold as sterile calls for USP <71>. A count or a screen can serve as a quick check across batches, if the report names it as one.
• Send separate, unopened vials. Sterility vials stay sealed and apart from the vial used for identity and purity. See how many vials to send.
• Plan for at least 14 days of incubation, plus shipping, and up to 21 days where the lab quotes that.
• Add endotoxin if your question is contamination. Endotoxin can be present when nothing grows; see endotoxin vs sterility, and how to choose a lab for endotoxin testing.
• Check the accreditation scope. Vanguard holds A2LA ISO/IEC 17025 accreditation (certificate 6377.01); its published scope does not cover USP <71> sterility, and Vanguard says accreditation applies to the specific tests and matrices in that scope. PharmLabs’ PJLA scope does not list sterility either.
• Test a batch as a batch. A seller releasing a batch should test the unit count its batch size calls for; see batch testing for vendors. A group test lets several buyers send one set of sealed vials from the same batch.

Published prices for these tests are in what endotoxin and sterility tests cost.

What HK Analytical offers for sterility

Our sterility test is Sterility (USP <71>, 14 days): the tested units incubate for at least 14 days and are checked for growth. It needs its own unopened vials, and the result covers only the units tested. The other tests, including endotoxin by LAL, can go in the same order. Results within days of receipt. Sterility (USP <71>, 14 days) is the one test that takes 14 days, because the method incubates for 14 days.

Every number comes with its raw data, in a signed record with a private link that you can check at hkanalytical.com/verify. Each report states how the client is related to HK Analytical. The example report shows the format. We do not hold ISO/IEC 17025 accreditation. Quotes are on request.