Concentrating Samples: In many cases, elute proteins off some type
of chromatography matrix with SDS sample buffer can keep a sample
volume minimal. If the volume of sample is too large, concentrating
the samples with a suitable method might be the easiest way to
increase the amount of protein samples available for protein
identification. Various micro-scale, protein-concentrating commercial
products claim a good volume reduction with good protein recovery.
Users may need to test these methods before committing their samples.
Running Gel: For SDS-PAGE, traditional Laemmli-style, Tris-Glycine
gel and its various modified versions, such as Bis-Tris gel or
Tris-HCl gel, are all acceptable for protein identification. Various
gel concentrations are acceptable. A user should choose the type and
concentration of a gel that gives the best separation for a given
sample. For some reason Tris-Tricine gel seems to be less compatible
with protein identification.
Staining Gel: Traditional coomassie (G-250 or R-250) staining is
good for protein ID. Colloidal coomassie staining kits from various
sources claim better detection limit (~ 5 ng BSA) and are all
compatible with protein identification. Other staining methods, such
as Zn/Cu staining, fluorescent dye staining, and silver staining are
also acceptable.
Excising Protein Band: Take a photograph of a gel before cutting
it. Avoid any direct contact with the gel with bare hands, light box,
or any other possible sources of keratin contamination. Try to
minimize the blank gel in a gel sample (it may reduce digestion
efficiency and peptide recovery). Put each gel band in a clean, 1.5 ml
micro-centrifuge tube and label each sample carefully.
Submitting Sample On-line: A first-time user will need to register
before submitting a sample (approx. 3 min. process). To submit a
sample, click the "Submit Sample" link and log on to your
account. Then select the Protein Identification link and you will see
a sample submission page. Select the number of samples you want to
submit, fill in the sample information, and click "Submit".
You will see the price quotation about your order on screen. Print out
three (3) copies of this quotation. Send one copy to us along with
your samples; use one copy as a quotation for applying a purchase
order from your institute (if paid by a PO), and keep one copy for
your record.
Payment: You may submit your order and ship samples to us before
having a purchasing order (you need to select "No P.O. at
Present" in the payment section). What your P.O. number is
available, you may submit your P.O online by logging in to your
account (or email/fax the P.O number to us). If you pay by a credit
card, you may fill in the card information online during online
submission (it is a secured link) or contact us later by
phone/fax/email (please note emails may not be secure).
Shipping Sample: All samples should be shipped via a type of
express service (FedEx, DHL, UPS, etc.) to minimize protein
degradation. Gel samples may be shipped at room temperature with a
standard envelope to minimize cost, or shipped in a container with ice
packs or dry ice container to prevent possible protein degradation (it
might be necessary if sample amount is very low or in a hot weather).
Also, please place each gel sample in a separate 1.5 ml microtube, and
then pack all sample tubes in one or more 50 ml centrifuge tubes and
cap the 50ml tubes tightly to prevent possible cracking of sample
tubes during shipment. Please include a copy of quotation printout and
a gel picture in a sample package. All solution samples must be
shipped in a dry ice container.
Checking Status: The processing of a sample will begin when we
receive the samples and valid billing information. A user can monitor
the status by logging on to his or her account. Please contact us if
there is some abnormality in the process.
Data Delivery: Usually, we will deliver results in five business
days after we have received the samples and payment information. By
default, we will deliver a report to the email account provided by the
customer.
Support: For technical questions regarding our service, you may
send an email to support@prottech.com. We will respond to your email
within 24 hours on weekdays. You may also contact us via phone or fax.
We also provide free, as well as fee-based, presentation and
publication support services. See "Support" for more
details.
