Crystallization Screening Service

The High-Throughput Crystallization Screening Center performs crystal-growth screening experiments in 1536-well microassay plates for both soluble and membrane biological macromolecules. We set up the experiments with a predetermined set of crystallization cocktails, image them weekly over six weeks, and send you those images including SONICC and UV-TPEF along with analysis software to view them. You send the sample, we do the rest.

  1. Sample requirements

As of April 2023, we only require 375 μl of protein sample for the entire 1536-well microassay plate set up (down from 500 μl of sample previously required). After you’ve made your reservation, please ship your sample in a labeled 1.5 ml microcentrifuge tube. We make the following recommendations:

    • Send only high purity, non-aggregated, stable protein samples.
    • Include all chemicals required for protein stability.
    • Use low (<25mM) buffer concentration. Avoid phosphate buffer (forms insoluble salts).
    • Strive for 10 mg/ml protein concentration when solubility permits.
    • Do not lyophilize your protein.
  1. Cost

The current cost for 1,536 different chemical conditions in the soluble or membrane screen is $400 US for academic, government and non-profit users. We also have a reduced cost Meritorious User Program for users at PUIs, at MSIs, and in under-resourced laboratories. For details see the flyer.

Users are billed after the sample has been set up (~4-6 weeks).

Please remember to acknowledge our NIH grant R24GM141256 if you find crystallization conditions using our services – and let us know so that we can feature your research!

We are happy to work with commercial users for proprietary samples, as well.  Please inquire about costs and options by emailing or send an inquiry at or at  Thanks!

  1. Sending your sample

Since May 2018 we have been using an online submission form.

      • To make a reservation, please email by the reservation deadline to reserve a space in the queue.  Include the following information in your reservation email:
        1. User name and contact information
        2. PI/Institution name and contact information
        3. Number of samples you will be sending, as well as approximate date you will be shipping the sample(s)

        You will receive an email confirmation from us for your reservation.

        • Once your sample is ready to ship, please fill out the online submission form including payment information. 
        • Send us an email to with the tracking number when you have shipped your sample so that we can keep an eye out for it.
        • Include the pdf form along with the protein solution in a clearly labeled 1.5 ml tube placed inside of a protective container (such as a Falcon tube).
          • For shipping, we make the following recommendations:
            1. Ship on Monday-Wednesday to reduce the risk of a weekend delivery delay.
            2. Use an insulated Styrofoam shipping container.
            3. Use dry ice for frozen samples.
            4. Use gel packs to maintain 4°C or 23°C sample temperatures.
  1. What you get
    • 1,536  microbatch-under-oil crystallization screening experiments are set up with your sample.
      • For the soluble screen, the assay includes an incomplete factorial based PEG/Salt/Buffer screen (688 cocktails) prepared in-house and chemically complementary screens purchased from Hampton Research which include: Crystal Screen HT, Index, PEGRx HT, SaltRx HT, PEG/Ion HT, Slice pH, Ionic liquid, Polymer Screen, Silver-bullets, and others (848 cocktails).
      • The membrane screen samples regions of detergent phase space particularly relevant to crystallization (1344 cocktails) prepared in-house with the Hampton Research PEGRx screen (96 cocktails), and the Molecular Dimensions MemGold screen (96 cocktails).
      • Typically the experimental error for delivery of cocktails and/or protein is < 5% (most often the error is < 1%) and we use control experiments to rapidly identify and address any issues that arise.
      • Click here to access the current crystallization cocktail lists.
    • Email notification and immediate access to color images of your experimental outcomes as they are recorded: (i) cocktail only prior to adding sample (control), (ii) plus images taken 1 day, (iii) 1 week, (iv) 2 weeks, (v) 3 weeks, (vi) 4 weeks and (vii) 6 weeks after adding sample.
    • Email notification and access to images from a Formulatrix Rock Imager 1000 SONICC (to identify chiral crystals) and UV-TPEF (to determine if crystals are biological). These images are taken either at ~4 weeks (23°C samples) or ~6 weeks (4°C or 14°C samples). Actual read time may vary slightly and is dependent upon availability of the system. Thus, there are a total of nine sets of images recorded over a period of six weeks.
    • Software options to view, annotate and analyze images as well as associated chemical data.
  1. Confidentiality

Information will not be publicly disclosed regarding any sample received for crystallization trials without the expressed written consent of the investigator(s).

Crystallization Center Policies and User Fees

  1. Acknowledgements

For information on the screens used and the Center the following articles may be of interest. If the high-throughput screening facility assists you in identifying initial crystallization conditions, please remember to acknowledge the NIH R24 National Resource grant in any publications. We suggest the following language: Crystallization screening at the National Crystallization Center at HWI was supported through NIH grant R24GM141256. These citations help us to track publications and PDB depositions, an important metric of productivity that will help secure future funding for the Crystallization Center. We request that description of the HTX Center in any publication reference one of the papers about our operations:

  1. Mailing list

We like to keep users up to date with new developments, e.g. improved cocktails, analysis software etc. If you would like to sign up for our mailing list to these notifications, please send a blank message to the following address:

  1. Special requirements

We can often accommodate special requirements, please contact us at