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Crystallization Kits | Crystallization Plates | Membrane Protein Kit | Optimization Kits | Optimization Reagents | Renaturation Kit

Crystallization Kits from Sigma-Aldrich offer:

Each screening kit consists of 48 or 50 different crystallization conditions. 10 mL of each compound are included in the kit; individual compounds are available in 100 mL package size.

Basic Crystallography and Extension Kits Crystallization Kit for Proteins for Automated Handling Cryo Kit Low Ionic Kit PEG Grid Screen Kit Membrane Protein Kit Crystallization Kit for Protein-Protein Complexes DNA Crystallization Kit RNA Crystallization Kit

The Basic Crystallography Kit is a rapid, empirical, and efficient screening method for determining the solubility and optimal starting conditions for the crystallization of biological macromolecules. Based on known and published data for various proteins, the Basic Kit uses a sparse matrix method and a minimal amount of protein sample to explore a broad range of buffers, pH, and precipitants (Jancarik, J. and Kim, S.H., J. Appl. Cryst., 24, 409-411, 1991).

The Extension Kit substantially increases the screening range of the Basic Crystallography Kit by providing a broader range of organic solvents, PEGs, and additives (divalent ions and stabilizers).

Both the Basic and Basic Extension Kit are based on the "salting-out" principle: that increasing the concentration of the precipitating agent depletes the macromolecules of bound water and leads to their precipitation and crystallization.

* As sole precipitant and/or as combinations

Helpful Notes:

Seeding at subcrystallization conditions may produce larger or more regular crystals.

Flow Diagram for Basic Crystallography Kit & Extension Kit

Basic Kit Datasheet including composition (142 kb PDF)

Extension Kit Datasheet including composition (110 kb PDF)

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This Kit is based on our Crystallization Kit for Proteins and the Crystallization Extension Kit for Proteins, which have been combined. The combined screen is delivered as Deepwell-Plate including 1 mL of each compound. This format makes it easy to fill crystallization plates either by automated liquid handling or with the help of 8-channel-pipets. The convenience of this kit saves a lot of time.

Helpful Notes:

Flow Diagram for Basic Crystallography Kit & Extension Kit

Extension Kit Datasheet including composition (129 kb PDF)

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The crystallization Cryo Kit is a rapid, empirical, and efficient screening method to determine the solubility and optimal starting conditions for the crystallization of biological macromolecules in the presence of a cryoprotectant (primarily glycerol). The screening range and probing ability of the Cryo Kit are comparable to those of the Basic Kit. A cryoprotectant is added to freeze crystals in an amorphous glass at -173 °C. The Cryo Kit is also based on the "salting-out" principle.

* As sole precipitant and/or as combinations

Helpful Notes:

Crystals cracking upon freezing indicates the need for a higher glycerol concentration or another cryoprotectant.

Due to the presence of a cryoprotectant, the Cryo Kit has an increased probability to produce false crystals of low molecular weight components, as compared to the Basic Kit. We recommend testing the nature of initial crystals at an early stage of experimentation by using controls without protein, by staining, or by X-ray defraction.

This kit consist of 50 ready-to-use solutions reflecting different crystallization conditions. When working with standard multiwell plates you may prefer to use just 48 different conditions. In that case we recommend omitting reagents 31 and 48 or two other reagents of your choice.

Flow Diagram for Protein Crystallization Cryo Kit

Cryo Kit Datasheet including composition (117 kb PDF)

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The Crystallization Low Ionic Kit for proteins is based on a screening protocol for monoclonal antibodies, which has been proven to be an effective screening method for soluble protein. The high-efficiency of this kit can be further improved by pre-determining the isoelectric point (pl) of the subject macromolecule followed by screening within a range at or near that value (within 2-3 pH units of the pl).

The Low Ionic Kit is based on the "salting-in" principle: that decreasing ion concentrations leads to a loss of electrostatic screening of charges on the macromolecules by low molecular weight ions. This loss of screening is compensated by the mutual screening of opposite charges on neighboring macromolecules. This leads to decreased macromolecular solubility and subsequent precipitation or crystallization.

* As sole precipitant

Helpful Notes:

The salting-in method of crystallography is extremely pH-sensitive. To further reduce the time, effort, and amount of sample needed, we recommend determination of the isoelectric point (pI) of the subject macromolecule followed by screening within two to three pH units of the pI.

Larger crystals may be grown by using seeding in salting-in experiments.

Small drops should be used in vapor-diffusion salting-in as drops will increase in size during the experiment.

Flow Diagram for Low Ionic Kit

Low Ionic Kit Datasheet including composition (103 kb PDF)

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The Crystallization PEG Grid Screening Kit for Proteins is a screening method for the determination of initial crystallization conditions for biological macromolecules like proteins.

The kit displays a range of conditions based on PEG 600 or PEG 6000 as precipitants and covers various buffers with pH values from pH 4.0 to pH 9.0. PEG is the most widely used type of precipitant, and size and concentration of PEG is critical for crystallization. On the other hand, pH is one of the mayor determinants for crystallization. The use of Crystallization PEG Grid Screening Kit enables determination of suitable conditions regarding these two crucial aspects. Further optimization may include the use of different types and concentrations of various salts.

* As sole precipitant

Helpful Notes:

Crystallization PEG Grid Screening Kit Technical Bulletin (89 kb PDF)

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The Crystallization Basic Kit for Membrane Proteins is a rapid, empirical, and efficient screening method to determine the best conditions for crystallization of hydrophobic macromolecules (primarily membrane proteins) in an empirical way. Based on known or published data for various proteins, broad ranges of buffers, pH, and precipitants in combination with a micelle-forming detergent are explored using the sparse matrix method with a minimal amount of protein. The crystallization principle of the kit is based on the screening of the hydrophilic, charged parts of the macromolecules by the binding of the detergent to hydrophobic areas of the macromolecules and subsequent reduction of their solubility. Detergent mediated contacts then lead to precipitation or crystallization of the screened molecules.

Helpful Notes:

We recommend using detergents that form small micelles, followed by use of detergents, which form increasingly larger micelles only as needed.

The ternary system of sample, detergent, and precipitant is a delicate system where small parameter changes can dramatically change interactions between sample-sample, sample-solvent, sample-detergent and detergent-detergent. Corresponding effects on macromolecular solubility and crystallization should be expected.

Temperature is an important variable in all detergent-driven crystallization experiments.

Streak-seeding can produce larger crystals from microcrystalline precipitates.

This kit consists of 50 ready-to-use solutions reflecting different crystallization conditions. When working with standard multiwell plates you may prefer to use just 48 different conditions. In this case we recommend omitting reagents 43 and 47, or two reagents of your choice.

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Crystallization Kit for protein-protein complexes is a rapid empirical screening method to determine the best conditions for the crystallization of such complex protein structures. This kit can also be used for determining the solubility of a certain macromolecule, screening a wide range of pH and different types and concentration of precipitants.

Protein complexes play a crucial role for studies of biological function. Based on own experience and a survey of successful crystallization conditions a specific screen was developed by S. Radaev and P.D. Sun (Applied Crystallography, 35, 674-676, 2002). This kit reflects the most probable conditios for crystallization of protein-protein complexes.

Helpful Notes:

Compared to the individual proteins, protein-protein complexes often require less concentrated precipitatns to crystallize. If data for individual compounds is available, this may give an indication, where one should mainly expect crystals to grow.

Crystallization conditions for oligomeric proteins like photosynthesis centres are highly individual and may need a customized screening procedure.

Crystallization Kit for Protein-Protein Complexes Technical Bulletin (92 kb PDF)

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The Crystallization Kit for DNA is an empirical screening method for the direct determination of suitable crystallization conditions for nucleic acids. The kit is developed according to the described method of Nowakowski, et al. (Acta Cryst., D55, 1885-1892, 1999.) The solution and crystallization conditions are empirically derived based on known or published crystallization conditions of nucleic acids, or DNA-protein complexes, especially of DNA-processing enzymes. Crystallization of protein-nucleic acid complexes is an area of increasing interest.

The Crystallization Kit for nucleic acids consists of 48 different formulations covering a range of different buffers (pH 5.5-8.0), different types of precipitants, esp. ethanol, 2-propanol, PEG, and inorganic salts including magnesium salts.

Helpful Notes:

For the crystallization of protein-DNA complexes length of DNA plays a mayor role. If initial screening does not yield sufficient crystallization, consider the possibility to change length of DNA.

Crystallization Kit for DNA Technical Bulletin (93 kb PDF)

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The Crystallization Kit for RNA is an empirical screening method for the direct determination of suitable crystallization conditions for RNA and DNA oligomers. Thus it provides a completion of our crystallization kit for DNA. The kit is developed according to the described method of Baeyens, Jancarik and Holbrook (Acta Cryst., D50, 764-767, 1994).

The Crystallization Kit for RNA consists of 48 different formulations covering a range of different buffers (pH 6.0-8.0), different types of precipitants (esp. PEG 400 and MPD), and inorganic salts including magnesium salts.

Helpful Notes:

Highly purified RNA is much easier to crystallize than heterogeneous (impure) RNA. Typically, it is much more difficult to purify larger RNA fragments to homogeneity than smaller ones.

In many case, questions can be answered by the investigation of certain fragments of natural RNA. Thus the use of smaller RNA fragments may be a possibility to improve crystallization.

Crystallization and crystal structure can also be influenced by other methods of RNA design, e.g. sequence variation, interhelical stacking, formation of protein-RNA complexes, or incorporation of modiied nucleotides.

Crystallization Kit for RNA Technical Bulletin (99 kb PDF)

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