Other services
Internal sequencing by chemical cleavage: please submit your project details for evaluation.

Sample amount
We require a minimum 20 pmol of blotted protein. 50 pmoles is very comfortable and generate unambiguous data.

Sample form
We accept PVDF blots or purified lyophilised/solubilised proteins.

Blotted onto a PVDF membrane (preferred)
The protein should be electroblotted from 1D or 2D gels and stained with Coomassie Blue (R250). Following staining/destaining, blotted membranes should be rinsed thoroughly with deionized water. The sample should be as concentrated as possible (15 to 20 pmol / lane) and several gel lanes may be loaded and submitted. The whole membrane may be submitted with a copy showing the band(s) of interest or the bands may be cut out and submitted, please indicate band molecular weight.

Protein in solution or lyophilised
30 to 150 µl of solution (H2O, Acetonitrile, Propanol). Pure lyophilised protein is also acceptable.
Protein should be free of detergent, salts and buffers. Please note that any amine-containing chemical present (e.g. Tris) will impair the adduction step.
Extra charge applies for this type of sample as we will run pre-purification at nominal fee to ensure complete removal of amine-containing impurities.

Sample purity
PVDF blots: well separated bands.
Liquid: Single purified proteins. Immunoprecipitation and affinity-column purified usually give good samples for sequencing.
In any case, a mandatory additional column purification step is applied to all incoming solution samples.

 Peptides & proteins with blocked N-terminal amino groups (e.g. acetylated, formylated) will not sequence by Edman degradation.

 High molecular weight proteins (over 75 kDa) may prove difficult to be analyzed. In our experience, the foremost reason is sample quantity and / or purity. However, reasonably pure protein bands and comfortable amounts will allow for unambiguous sequence calls. Please contact us before sending your sample.

 Unmodified Cys and glycosylated residues will give a blank cycle (i.e. residue is cleaved off the peptide chain but is not detected by HPLC at 270 nm).

 Sample quality is critical. Any impurity that interfers with Edman’s chemistry (mainly amine-containing chemicals) will lead to poor results.

Pricing
A set up fee (minimum charge) applies that includes the first 5 residues. The latter is sufficient for confirmation sequencing. If you are studying an unknown protein and wish to search databases for homologous sequences we would then recommend at least an additional 5 residues for useful database search results. Please contact us for an offer.

Sending your sample
A sample submission form is available for your convenience: Order
Please send your PVDF membrane(s) or tube(s), clearly labelled and wrapped with parafilm in a padded envelope. Include your Institutional Purchase Order (mandatory) and the sample submission form or a letter describing your sample(s) and indicating the number of residues you wish to sequence. Should you require a database search, please indicate protein details (species, suspected family, etc.).

PVDF samples: copy marking band(s) of interest, approximate size, amount loaded.

Solution samples: sample name, approximate size, total amount (µg), concentration (µg/µl), volume (µl) and solution content (H2O, buffers…).

Please send at room temperature using express courier or postal services to:
GENOSPHERE BIOTECHNOLOGIES
Protein Analysis Services
2 rue des Gravilliers
75003 Paris
FRANCE
tel: 01 42 71 70 21 (local dialing)
For a faster processing of your order and safer tracking of your samples, please advise our Customer Services of your sending a sample with courier airway bill number if available: info@genosphere-biotech.com.