High-Throughput Screening Services

High-throughput screening services from Boster Bio

High-throughput screening (HTS) tests a compound collection against a biological target or cell system in microplates to find molecules that produce a measurable effect. Boster Bio and its partner labs deliver the core of a screening program: assay miniaturization, a pilot screen, the primary screen, and hit confirmation with counter-screens.

Some projects arrive with a validated assay that only needs to be scaled. Others arrive with a target and a hypothesis, and the assay has to be built and proven before any library plate is screened. Both start with the same goal: a short list of hits that reproduce and are worth a chemist's time.

HTS sits after target validation and before hit-to-lead chemistry. Everything in a campaign, from assay design to counter-screening, exists to keep that hit list honest.

Assay formats

The assay format is chosen before the first plate is screened, and it decides what the hit list can tell you. A large library and fast automation cannot rescue an assay that asks the wrong question.

The right format depends on modality, how robust the assay is likely to be at scale, and the readout you need: a yes/no hit call, a potency value or a kinetic profile. We work through these trade-offs with you when scoping the project. For metabolic programs, Boster's compound screening services cover donor-derived adipose tissue models.

Assay development and miniaturization

Many projects start without an assay that is ready for automation. The work then begins with the target's biology, a detection chemistry, and proof that the assay holds up at small volumes and automated timing. Boster's assay services cover this groundwork, and ELISA-format readouts can be built through our ELISA assay development services.

1. 1

   Feasibility

   Confirm the target can be expressed, purified or stably transfected, and that it gives a measurable signal.

2. 2

   Optimization

   Tune reagent concentrations, incubation times, buffer and detection settings to maximize signal over background.

3. 3

   Miniaturization

   Scale the assay from 96-well volumes into 384- or 1536-well plates without losing signal quality. Many assays need rework at this step.

4. 4

   Automation transfer

   Move the protocol onto automated liquid handling and plate reading, then re-validate under those conditions.

5. 5

   Validation

   Run replicate plates to confirm the assay meets agreed statistical thresholds before it is cleared for the library.

Rushing any of these steps is a common cause of an unusable hit list: too many artifacts, or a signal window too narrow to trust.

Compound libraries

The library sets the limit on what a screen can find. You can screen your own compound collection or discuss library options with us; availability is confirmed at quote.

Diverse libraries

Broad chemical space across unrelated scaffolds. The usual choice for a novel or poorly characterized target.

Focused libraries

Compounds enriched for a target class such as kinases, GPCRs or proteases, which can raise hit rates when the mechanism is known.

Repurposing libraries

Approved or clinically tested drugs screened for a new indication, so any hit arrives with existing safety and pharmacokinetic data.

Fragment libraries

Small, low-molecular-weight compounds screened at high concentration to find weak but tractable starting points. Available on request.

Library size is not library quality. Poor diversity, degraded stock plates or heavy structural overlap can make a large collection underperform a smaller, curated one. When we scope a screen, we review compound purity, stock-plate age and scaffold overlap with you, so the hits are not one scaffold found a dozen times.

Plate formats and readouts

Automation makes the throughput possible, but the platform has to fit the assay. Plates move between liquid handlers, incubators and readers on a fixed schedule, and an assay that cannot tolerate that timing will fail however sound the biology.

Well format trades throughput against volume per well. 96-well plates give more working volume and suit assay development. 384-well plates hold four times as many wells with tighter tolerances. 1536-well plates, the usual entry point to ultra high-throughput screening, cut volumes to a few microliters and need very precise liquid handling and a wide, stable signal window. Format and readout are chosen per assay and confirmed at quote.

Readout technology	What it measures	Typical use
Fluorescence intensity / polarization	Light emitted or depolarized by a labeled molecule	Binding and enzymatic assays
Luminescence	Light from a chemical or enzymatic reaction	Reporter-gene and ATP-based viability assays
Absorbance	Light absorbed by a colored product	Simple colorimetric enzyme assays
High-content imaging	Cell morphology, localization, or population-level features	Phenotypic and mechanism-of-action screens
Label-free biosensing	Mass or refractive-index change on binding	Direct target engagement without a tag

Hit confirmation and counter-screening

A primary hit list is a set of candidates. Many will not survive retesting, and confirmation is how you find the ones that do.

• Retest: the same compound at the same concentration, re-run to filter out pipetting or plate-edge artifacts.
• Dose-response confirmation: a full concentration curve to establish potency and show the effect scales as expected.
• Orthogonal assays: a second, independent method to confirm the compound acts on the intended target rather than on a quirk of the first assay.
• Counter-screens: assays that catch compounds interfering with the detection chemistry, such as autofluorescent or colored compounds and aggregators.
• Selectivity profiling: testing against related targets to separate selective hits from promiscuous binders. Available on request.

Confirmation removes the hits that were never real, so chemists spend their time on compounds worth the effort.

Hit hand-off to your chemistry team

The core service ends with a confirmed hit list and the data behind it. The hand-off package is built so your chemistry team can start triage without re-running basic checks:

• Confirmed activity: retest results and dose-response curves for each confirmed hit.
• Interference checks: orthogonal and counter-screen results side by side.
• Known liabilities: reactive groups, known problem scaffolds or poor solubility, flagged where seen.
• Open questions: what the data does not yet support, and which assays would answer it.

Further follow-up assays are available on request and scoped separately.

Quality metrics and deliverables

Each stage is checked against statistical criteria agreed before screening starts, not judged afterwards by whether the hits look right.

At the end of a campaign you receive the raw and normalized plate data, the hit-calling logic used, dose-response curves for confirmed hits, counter-screen results, and a written summary of what worked, what didn't and what the data supports. That lets your team check, and reproduce, the result.

Pilot screens and primary screens

Screening a full library before the assay has proven itself at scale is an expensive mistake. A staged plan keeps spending in line with what is known at each point.

1. 1

   Assay ready

   Your validated assay, or one built through the assay development steps above, passes the agreed quality criteria before any library compound is used.

2. 2

   Pilot screen

   A subset of the library, sized at quote, runs through the full automated workflow to confirm Z′, plate uniformity and a sensible hit rate.

3. 3

   Primary screen

   The selected library is screened once the pilot clears its quality bar, with the same statistical checks applied plate by plate.

4. 4

   Hit confirmation and reporting

   Hits are retested, dose-responded and counter-screened, and the data package comes with a recommendation on which hits merit chemistry follow-up.

Each stage ends in a go, adjust or stop decision, so budget goes only to work the data supports.

What to send and what to expect