Protein gel spots, gel strips, IP sample protein identification

BiotechPack Bio combines MALDI-TOF mass spectrometry system and LC-MS/MS mass spectrometry system to provide professional and accurate protein spot, strip, IP sample, and Co-IP sample protein identification services. Identifiable samples include: protein strips separated by 1D-SDS PAGE, protein spots in 2DE PAGE, protein expression products, and co-immunoprecipitation (Co-IP) samples. The pre-processing of protein samples for identification is strictly in accordance with the article published in Nature Methods: Universal sample preparation method for proteome analysis, ensuring higher peptide coverage in the identification test. The principle of mass spectrometry identification is based on the shotgun method: the protein bands or protein solution are enzymatically digested into peptide mixtures, which are separated by high-performance liquid chromatography to obtain several relatively simple components, and analyzed by high-resolution mass spectrometry. The retrieval software compares the secondary mass spectrometry information with the corresponding database, and based on the matching score and mismatch filtering, the exact sequence of the peptides can be obtained, and then the complete sequence of each protein is spliced together, thus achieving protein identification.

Protein Mass Spectrometry Identification Process

Protein Identification Process Based on Shotgun LC-MS

About Samples

1D SDS PAGE / 2D PAGE Gel Samples:
1. Coomassie Blue, SYPRO Ruby, and Silver stain samples can all be used for protein identification testing;
2. Silver-stained samples may be incompatible with subsequent mass spectrometry analysis. We recommend using the following products or experimental procedures for silver staining:
ProteoSilver Plus, Sigma (Product # PROTSIL1 or PROTSIL2)
Dodeca Silver Stain, BioRad (Product # 161-0481 or 161-0480)
3. Do not perform destaining on silver-stained samples

Liquid Samples (In Solution Format):
1. If the protein amount in the sample is >10ug, we have no requirements on the buffer system of the sample;
2. If the protein amount in the sample is <10ug, try to minimize the use of surfactants such as SDS during sample preparation and pay attention to reducing salt concentration;
3. When submitting samples, be sure to provide the buffer system of the sample and the estimated protein content in the sample;
Co-IP Samples:
1. If your eluted sample needs to be run on a gel, prepare the sample according to the 1D SDS PAGE sample preparation requirements;
2. If you submit the eluted sample directly, we recommend using the HPH EB (0.5 M NH4OH, 0.5 mM EDTA) buffer system for protein elution to ensure the elution buffer system is compatible with subsequent mass spectrometry experiments;
Sample Transportation:
1. We recommend lyophilizing samples for transport, as proteins in lyophilized samples are very stable.
2. Liquid samples are recommended to be transported on dry ice; short-distance transport can use ice packs.

Precautions: When using mass spectrometry for protein sample identification, wear gloves and a hairnet during sample preparation to minimize contamination of the sample with keratin.

Research Case

This project involved a teacher from the Institute of Biophysics, Chinese Academy of Sciences, sending her Co-IP samples to us for protein identification. Some of the results obtained are shown in the following figure:

Research Case of Protein Spot, Strip, and IP Sample Protein Identification

From the figure, it can be seen that our result report includes the Accession Number of the identified protein, Peptide coverage, identified peptide information, modification information of the identified peptides, and a detailed description of the identified protein.

Chinese/English Project Report:

In the technical report, BiotechPack will provide you with a detailed bilingual (Chinese and English) technical report, which includes:

1. Experimental Procedures (Chinese and English)
2. Relevant Mass Spectrometry Parameters (Chinese and English)
3. Mass Spectrometry Images
4. Raw Data
5. Detailed Information on Identified Proteins

One-stop Service for Protein Spot, Strip, and IP Sample Mass Spectrometry Identification

You only need to place an order and send the samples
BiotechPack's one-stop service completes: sample processing, machine analysis, data analysis, project report