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Research Programs

Proteomics Services

 
 
  1. Sample Turn-around Time
  2. Sample Submission
  3. Data Analysis
  4. Sample Preparation

 

I. Sample Turn-around Time

As we are a Shared Services Facility, samples are submitted to us for analysis by researchers throughout the University of Maryland, Baltimore, in addition to other universities. Accordingly, there is a queue for sample processing. We process samples in the order in which they are received and we do our best to ensure the timely analysis of all samples. Please allow for an average turn-around time of 15 business days from the time your sample is brought to us. For the feasibility of processing "rush orders" (**Rush orders are charged double the regular price.**), please speak with us prior to submitting your sample.

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II. Sample Submission

Please place all orders using the University of Maryland, Baltimore's BIORESCO freezer program website: http://cf.umaryland.edu/freezer/. After logging in, select your requested service(s) from the "Proteomics Services" link in the "CORE Services" box on the right-hand side of the page. When you stop by our Facility (Bressler Research Building, Rm. 7-050) to drop off your sample, please be prepared to briefly discuss with us all details pertaining to how your sample is prepared. The quality of our proteomic analysis of your sample is greatly affected by the amount of information about your sample that you provide; the more details you can provide about your sample preparation, the better. Refer to the section on "Sample preparation" for more guidelines.

Please note that the Proteomics Shared Services Facility currently does not have enough capacity and throughput to accept the following samples: tissues (both human and animal) and unprocessed biological fluids such as plasma, urine, and saliva.

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III. Data Analysis

We will contact you once we have finished analyzing your sample to discuss the proteomic data with you.

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IV. Sample Preparation

As a Shared Services Facility we offer proteomics services and the methodologies listed here are only used as a general guideline. However, by adhering to the following guidelines for sample preparation, you will greatly enhance the quality of the data from the proteomic analysis of your sample. For certain experiments, additional method development may be required prior to analysis by mass spectrometry.

A. Avoiding Keratin Contamination

One problem common to both 1D or 2D-gel/MS and LC/MS methods is keratin contamination. Keratins are naturally occurring structural proteins and more often arrive in the sample through the environment rather than from natural abundance. Fingerprints, hair, dead skin flakes, wool clothing, dust and latex gloves are common source of contaminating keratins. If keratins are present in concentrations greater than that of the protein of interest, their abundance will overwhelm the analytical capacity of an LC/MS system and obscure the proteins of interest. This is particularly problematic when performing data dependent mass spectrometry, as the peptides from the more abundant keratins will be selected for MS/MS analysis, providing little or no information about the actual proteins of interest. However, in low concentrations, compared to the protein of interest, keratins are not a problem at all.

Listed below are few hints that will help you to minimize keratin contamination:

B. Gel Electrophoresis and staining

Always wear gloves, use a clean gel running apparatus and solutions, and run your gel in a very clean environment. This will help to minimize possible contamination of your protein samples with keratin (see "A. Avoiding Keratin Contamination").

C. Excising Gel Bands

We offer protein band/spot excision services. However, if you prefer to excise your protein band(s)/spot(s) of interest yourself, please adhere to the following guidelines:

D. Preparation of Protein Samples in Solution

We prefer that you prepare your samples in a volatile buffer that can be removed by either lyophilization or vacuum centrifugation. Whenever possible, please dissolve your sample in ammonium bicarbonate, acetonitrile or a water-based buffer. Please avoid including metal ions in your buffer. If buffer exchange of your sample is required following sample submission, additional charges will be applied. If detergent is needed in order to keep your protein in solution, please use those detergents that are compatible with mass spectrometry analysis, which are typically detergents with a high crucial micelle concentration. (The formation of detergent micelles creates problems for mass spectrometry analysis such as signal suppression and peak broadening). Please note that SDS and Triton X-100 are generally NOT compatible with mass spec analysis so please discuss possible alternatives with the Proteomics Shared Services Facility staff.

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This page was last updated on: January 21, 2010.