Frequently Asked Questions

How do I place my order?


Orders can be placed for standard products using a credit card via the secure PayPal payment function on the Compound Cloud website.



Orders can be placed offline by sending an official purchase order to info@bioascent.com, or by phone at +44 1698 534002.

What is the order process?

You place your order by either using the payment function on our online shop, uploading your official purchase order, or by emailing your official Purchase Order to us. We need to know the following:

  • The Product code(s) of the items you are purchasing (automatically provided when paying online).
  • contact details for both billing and shipping addresses, including a name, email address and phone number, in case we have any questions.
  • For EU customers, we require your VAT number, or alternatively a VAT exemption certificate.
  • Purchaser contact information of person authorising the purchase (name, email address, phone number) – we will send the order confirmation to this address.

We will use the contact details to send you a written order confirmation when we process your order, stating the price of goods and services, delivery address and expected shipping date and any other relevant information.

When shipping we will email you to confirm your products are on their way, including the courier tracking reference number to allow you to track.

How can I pay for my product?

Compound Cloud/BioAscent accepts credit card, cheques, bank and wire transfer as methods of payment. For questions, or further details on our bank account, please email finance@bioascent.com.

Unless already paid by credit card, full payment instructions will be detailed on the invoice which will be sent to the billing address by email.

Invoices should be paid no later than 30 days after the invoice date, and Customers must themselves pay any bank charges that are incurred in making the payment.

Do we charge VAT?

Our prices are presented on Compound Cloud, exclusive of VAT.

VAT only applies to customers in the European Union (EU)

A VAT number must be provided for Orders from Customers within the European Union to ensure the sale is zero-rated.

If the Customer is not VAT registered or does not provide a valid number, BioAscent must charge the 20% UK VAT rate on the order.

If the Customer is located within the UK and the Customer is eligible for zero-rated supplies or VAT exempt, the Customer must provide BioAscent with a valid certificate along with the order, otherwise BioAscent must charge the standard rate of 20% VAT.

Is the product in stock?

BioAscent maintains stock of all Products. In the event of issues with stock, BioAscent will contact the Customer as quickly as possible and inform them of planned delivery date.

How long will it take to receive?

For items in stock, we will ship as quickly as possible. As we deliver all our products on dry ice, we will ship on a suitable day of the week to ensure arrival at the Customer location on a work day. We will provide tracking number details from the courier to allow the Customer to monitor the shipment progress.


How do you ship the Product?

Unless agreed otherwise, we will send your Products on dry ice to maintain their quality during shipping, using our standard BioAscent shipping SOP, and delivered using courier selected by BioAscent. BioAscent will confirm shipment of Products to the client on the date the Products are transferred to the courier. Where possible, BioAscent will also provide the Customer with a shipping tracking number.

What do I do if my Product is damaged in transit?

We want you to receive your compounds, and be able to get straight to your experiment, so maintaining the quality of your Products is important to us.  The many thousands of plates we have shipped internationally arrive successfully. However you should immediately inspect Packaging and the Product upon receipt, and notification of damage, shortages or defects should be communicated to BioAscent immediately by e-mail or phone.

If the Product should be damaged or defective, BioAscent will undertake best endeavours to rectify the issue in discussions with the Customer.


Where did you source the compounds?

Compounds were commercially available and sourced from various suppliers. For more information, see here.

How were the compounds selected?

The Compound Cloud collection was originally part of MSD’s screening collection and had been selected by Organon/Schering-Plough/MSD medicinal chemists.


Compounds were selected using drug-like properties e.g.


  • Lipinski’s Rule of 5 compliance
  • polar surface area <120
  • avoiding structural features known to result in problems in biochemical assay &/or late candidate drug optimisation phase
  • focus on attractive chemotypes and on compounds found in recent drug discovery projects

How many screens have you performed on each target class?

All compounds were directed towards targets of interest such as GPCRs, kinases, nuclear receptors, ion channels and transporters.



Analysis using Vertex Kine “2-0” kinase likeness model* shows 27.5% are classified as “kinase-like”.
* Kinase-likeness and Kinase-Privileged Fragments: Toward Virtual Polypharmacology Alex M. Aronov,* Brian McClain, Cameron Stuver Moody, and Mark A. Murcko. J. Med. Chem. 2008, 51, 1214–1222



Various GPCR finger-printing were used and typically 15-24% of compounds were found to be similar (Tanimoto similarity >0.67 to 0.64) to members of GPCR reference drugs.


PPI Inhibitors

One of our customers has filtered the entire collection against their own filters for PPI inhibitors, and selected ~20,000 compounds for screening.
Overall we are unable to share any screening data (e.g. hit-rate in each target class) associated with the compound collection as the information is proprietary of MSD/Schering-Plough/Organon.

How was diversity determined?

Diversity of the Compound Cloud collection was done by initially selecting a diverse subset based on structural fingerprints, followed by a database hole-filling exercise, where principal components derived from calculated descriptors relevant from protein:ligand interaction were used to select additional diverse compounds, ensuring full coverage of the physico-chemical space of the whole collection.

What kind of filters are used regarding the evasion substructure?

Nearly 200 proprietary filters for unstable/undesirable fragments (based on filters derived in Organon, Schering-Plough and Merck) were applied. 95 fragment filters were used to avoid compounds with unstable, chemically reactive or extremely toxic features; other filters were used to avoid bio-reactive or known assay interference compounds.

What is your policy in the filtering of physicochemical parameters?

The standard policy is to bias towards Lipinski’s rule of five compound distributions, but to allow exceptions in one or two properties where compounds bring extra novelty/diversity.


What can I do with 2uL @ 2mM?

2uL @ 2mM is an optimised amount to provide enough compound to provide a typical primary assay concentration of 10uM in a typical 384-well assay reaction volume, once diluted. The principle is that you dilute into the source well first, shortly before the assay, before transferring a diluted amount to the assay well. In effect, this makes the supplied plate a “Near-Assay Ready” plate. You can learn more at our blog post.

Do you have larger amounts/volumes?

Follow-Up Samples are as standard supplied in the larger 5.5uL @ 10mM amount. This enables the majority of follow-up work. However should you require larger amounts (e.g. some 96-well) you can order a 32.5uL @ 10mM amount. Please contact us for more information.
All of these sample amounts are only accessible as follow-up to your primary screen using a Screening Library.

How are the plates labelled?

The plates are labelled with a Code-128 barcode on the east side of the plate. They will also can have an eye-readable text label applied to the west side denoting the library name and copy number. In the case of Custom Screening Libraries, the text may be specified by yourself for your administrative/handling convenience.

I have an acoustic liquid handler (Echo), which needs compound in acoustic plates?

Our Custom Screening Libraries and Follow-up Samples can be supplied to you reformatted into Echo-certified acoustic plates (Labcyte 384 or 1536-well). To enable this option, please contact us when placing your order.

Currently Ready-Made Screening Libraries are not available in acoustic plates.

Single-use plates are great- but what if I drop it, or my other reagents fail?

Accidents do happen, albeit rarely. The simple solution is to purchase another copy of the library from Compound Cloud. It’s still a cheaper option overall versus (a) obtaining the compounds from suppliers, and performing all necessary operations (including reformatting) to get small volume into the right plate format, and (b) storing master plates of this in a format ready to stamp out a new copy.
A replacement copy (from the same source stock) can be delivered to you within a few days.

Follow-up Samples - how do I access/open the microtubes?

Follow-Up Samples are supplied in ‘REMP’ tuberacks, which are standard-sized 384-well plates, but in fact each well is actually a tiny microtube.

Every liquid handler can access them as usual, only the method of de-sealing them is a little different, but still very simple.

Rather than peeling off a plate seal, you pierce the wells using a “piercing lid”, which we supply in your shipment. These are very simple to use – place the piercing lid on top of the plate, push down hard (until you see the seals are pierced), and remove the lid. The samples are now available to access by liquid handlers as normal.

Follow-up Samples - I'm not sure my liquid handler can deal with microtubes?

The standard plate-type of Follow-Up Samples (REMP tuberacks) are industry standard size (SBS format) and therefore exactly the same footprint and well spacings as you are used to; the depth of the wells is effectively identical to e.g. Greiner’s 384-well V-bottom polypropylene plate (Greiner 2.9mm vs DTbR384 3.02mm).  They are easily de-sealed using the supplied piercing lids, and have an extremely small dead volume.
However should you still prefer to receive a different plate type, we can perform the transfer for you in the appropriate dehumidified conditions.

Follow-up Samples - what if I want to reseal my microtubes after piercing?

A tuberack can be effectively resealed by placing the supplied piercing lid back onto the rack (and optionally freezing the plate, for longer term storage).


What data do I receive with my samples?

You will receive platemap data as both .csv file and .sdf files (with compound structures) which include all the information you will require, including the compound ID code, well, molecular weight, volume and concentration.

Phenotypic Toolbox orders will additionally be supplied with a biological annotation package.

My database needs specific column headers?

We can supply a platemap in the format you require for a small additional fee.