Proteomics Services

Protein Sample Submission

Sample Type

• Protein analyte samples may be natural proteins, recombinant proteins, antibodies or enzymes.
• The following requirements are applied to recombinant protein and purified protein or antibody samples.

Sample State

• The target protein should be in its active form and remain to be active under the defined assay conditions.
• The proteins should be stable at 4°C for at least 10 h and at the required assay temperature for 2 hours.
• During sample processing, those containing protein precipitation will not be used and customer will be informed.

Sample Purity

• The target protein should be at least 85% pure determined by one of the stringent analysis methods, such as electrophoresis gel, Western blot, FPLC, or Mass analysis.
• The sample should be free from contaminants, such as nucleases, proteases, or free dye molecules used for protein labeling. The ratio of optical absorption of 280/x (x=max. absorption of dye molecule at a longer wave length, such as cy3 at 550 nm (e 150,000 µM-1 cm-1) and cy5 at 650 nm (e 250,000 µM-1 cm-1) should be indicative of the presence of excessive dye molecules.

Sample Amount

Binding Assays

• The required protein amount differs and will be determined by protein binding affinity and the objective of the chip assay.
• Typically, each assay requires about 250 µL of the sample at µM concentration. This is about 0.25 nmol or 25 µg of a protein (Mw 100 kDa). The binding of Kd ~ 1 µM can be detected under the condition.
• Proteins of higher binding affinities will require less than the amount given and of lower binding affinities will require more than the amount given.

Enzymatic Assays

• The required protein amount differs and will be determined by enzymatic activities.  The recommended amount of the enzyme by the provider is usually used.
• Typically, each assay requires about 250 µL of the sample.

Packaging and Shipping

• Please transfer your sample to a 1.5ml microcentrifuge tube for shipment (0.5 ml or smaller PCR tubes can crack when frozen). Be sure the tube labels match those listed on your sample submission form.
• If you want to seal the tubes or hold them in a rack, please don’t use tape (it will crack when frozen), use parafilm.
• Pack the sample with ice in a thermal insulated shipping box.
• Ship the package by overnight carrier for delivery the next day.
• Note – Do not ship samples on Friday as they will sit over the week-end and deteriorate.  Wait until the following Monday and ship for Tuesday delivery.

Mail the package to:
Attn: Sample Receiving
LC Sciences
2575 West Bellfort St., Suite 270
Houston, TX 77054