Short answer. There is no single best antibacterial screening software, because the tools sold into discovery split into three groups that do genuinely different jobs: places to keep your data (CDD Vault, Dotmatics, Benchling), engines that model a compound against a molecular target (Schrodinger, and the open-source docking stack), and layers that score a compound against named bacterial strains. A small antibacterial team usually needs one from the first group and one from the third. Buying two from the same group is the common and expensive mistake.
This is written for a team of roughly five to fifty people running an antibacterial program on a real budget, not for an enterprise procurement committee. The comparison below is on the things that decide the purchase at that size: whether the read-out is per strain, whether the price is published, what happens to your unpublished chemistry, and how long it takes before the tool changes a decision.
The categories, compared
Pricing is only shown where the vendor publishes it. Most discovery software in this space is quote-based, which is itself a fact worth planning around: a quote cycle adds weeks before you know whether you can afford the thing.
| Category | Examples | Unit of work | Pricing | Best for |
|---|---|---|---|---|
| Registry, ELN and SAR archive | CDD Vault, Dotmatics, Benchling | A compound record | Quote-based, per user | Remembering what you made and what it did. Essential, and not a screening tool |
| Physics and structure-based modelling | Schrodinger, AutoDock Vina, PyRx | Compound against a target | Enterprise licence, or free and open source | Programs with a validated target and a structure to dock into |
| HTS data analysis | Genedata Screener, Dotmatics | A plate, and the curves on it | Quote-based, enterprise | Teams already running plates at volume in house |
| Public bioactivity data | ChEMBL, PubChem | A measured activity record | Free | Anyone willing to spend an afternoon querying per compound |
| Free academic wet screening | CO-ADD | A submitted compound on a real plate | Free to eligible academic groups | Academic labs that can wait, and can accept eventual open publication |
| Strain-level prediction and triage | Antibacterial | Compound against strain | Published: $149, $499 and $1,490 a month | Deciding which compounds in a series earn plate time, and why |
Why a general discovery suite underserves an antibacterial program
The dominant tools were built around compound times target. That framing works when the biology is a purified human enzyme. It quietly breaks for bacteria, because two compounds with identical target affinity can differ by a hundredfold in whole-cell activity for reasons that have nothing to do with the target: one crosses the outer membrane, the other does not, or one is a substrate for an RND efflux pump.
That is why a docking score is a poor proxy for an antibacterial decision. The relevant unit is compound times strain, and the same molecule can be excellent against MRSA while being completely inert against Gram-negative bacteria. If a tool cannot express that difference, it cannot rank your series.
What to actually check before you buy
- Does the read-out name a strain? If the output is a single activity score with no organism attached, it is a target tool being sold into an antibacterial program. Ask to see output for MRSA and for A. baumannii side by side.
- Does it tell you why, or only what? A ranking without a mechanism is not a defensible reason to kill a series in a project meeting. A named mechanism, whether that is beta-lactamase hydrolysis, target modification or efflux, is what survives scrutiny.
- Does it report its own uncertainty? A genuinely novel scaffold has thin published support and any honest model should widen its band and lower its confidence. A tool that returns the same confident number for a well characterised fluoroquinolone and for a scaffold nobody has published on is hiding the one thing you needed to know.
- What happens to your structures? Read the terms on training data and on data sharing. This is the practical reason a company with unpublished chemistry cannot simply route everything through a free academic scheme, however good it is.
Where the free options genuinely win, and where they stop
Two are worth knowing properly. ChEMBL, from EMBL-EBI, holds measured bioactivity extracted from the literature, including MIC values against named organisms. It is the substrate under most prediction in this field. What it will not do is rank anything: it is a database, not an opinion, and getting a usable answer for one compound is an afternoon of manual querying that does not scale to a four hundred compound series.
CO-ADD, run by academics at the University of Queensland, screens compounds for antimicrobial activity free of charge for academic groups, against a panel of key ESKAPE pathogens plus two fungi. It is a real wet screen and it is genuinely free, which is a better deal than anything commercial for an eligible lab that is not in a hurry. The constraints are eligibility, queue time, and the fact that results feed into an open-access database after a confidentiality period. For an academic PI those are acceptable. For a company with a filing deadline and unpublished chemistry, usually not.
The sequence that costs least
For a team of this size the cheapest order of operations is: triage in silico, then confirm a much smaller set on a plate. Prediction is cheap and occasionally wrong; a plate is expensive and right. Spending the expensive resource on compounds the cheap one already flagged as dead is the waste worth removing, and it is usually worth more than any incremental improvement in the assay itself. The economics of cutting the library before it reaches a plate are covered on the high throughput screening page.
One practical note on the confirmation step. Contract research organizations return panel results as formatted PDF reports, and pulling those numbers back into your own SAR table by hand is a reliable source of transcription errors. If that becomes a weekly chore it is worth pointing a document data extraction tool at the reports rather than retyping MIC values into a spreadsheet.
Can antibacterial activity be predicted before testing?
Activity can be predicted as a band with a stated confidence, not as an exact number. Broth microdilution reads in doubling dilutions, so even the bench measurement is plus or minus one step, and a prediction that claims more precision than the reference method is claiming something the method cannot deliver. A predicted band of 1 to 4 µg/mL with the analogs it rests on is more useful than a confident 2.
How much does antibacterial screening software cost?
Published pricing in this category is rare. Registry and enterprise platforms quote per user after a sales conversation, and the open-source docking stack is free but carries setup and expertise cost instead. Our own plans are listed publicly at $149, $499 and $1,490 a month, which is deliberate: at this team size, a quote cycle that takes three weeks is itself a cost, and you should be able to work out whether a tool fits your budget before you talk to anyone.
What is the difference between screening software and a screening service?
Software gives you an answer you generate yourself, in seconds, as many times as your plan allows. A service puts your compound on a real plate and returns a measured result, in weeks, priced per project. They are not competitors. The software decides what goes to the service, and the service produces the number you eventually publish or file.
The honest recommendation
If you are a small biotech with an antibacterial series, buy a registry you can live in for five years and a strain-level triage layer, and skip the enterprise modelling suite until you have a validated target and a structure worth docking into. If you are an academic lab, use ChEMBL and apply to CO-ADD first, and add a prediction layer when the queue becomes the bottleneck.
If the deciding question is which twelve of four hundred analogs go on the plate this month, that is precisely what MIC prediction software is for, and at deck scale what compound library screening software is for. The screen at the top of this page runs without an account, so the fastest way to judge it is to paste in the compound your team is currently arguing about and see whether the mechanism it names matches what you already suspect. Full plan details are on the pricing page.