Wednesday, 25 March 2015

Label-free Quantification VS Stable Isotope Labels



Quantitative proteomics, as an analytical chemistry technology to determine the amount of proteins in certain samples, can not only provide the lists of proteins identified in a certain sample but can also yield information about the differences between samples. Generally speaking, quantitative proteomics is mainly performed by 2-DE (two-dimensional gel electrophoresis) and mass spectrometry (MS). MS technology in the past decades has gained increasing popularity in this field.
Basically speaking, the relative and absolute quantification includes Label-free proteomics (Label-free quantification) and Stable isotope labels. Following are a brief introduction about the two methods.
Label-free quantification
Label-free proteomics is a quantification method in mass spectrometry ans the aim of it is to determine the relative amount of proteins in two or more biological samples. Other methods for quantification need to use a stable isotope containing compound to chemically bind to and label the protein, however, label-free quantification does not. According to scientific research statistics, Label-free quantification can provide higher dynamic range of quantification. That is to say, using this method, we can measure significant changes within a complex mixture or across an entire proteome in a single experiment.
Stable Isotope Labels
Compared to label-free quantification, stable isotope labels is a method that’s more costly and time-consuming for relative quantification, though less sensitive to experimental bias than label-free quantitation. Relative quantitation methods include ICAT (isotope- coded affinity tags, N-terminal labeling, iTRAQ (isobaric tags for relative and absolute quantitation), etc.
With years of experience in providing proteomics services, Creative Proteomics has a high reputation among customers worldwide. Label-free method in Creative Proteomics are for both relative and absolute quantification, which is a rapid and low-cost alternative to other quantitative proteomic approaches. As a customer-oriented company, Creative Proteomics emphasize customer experience. If you want to know more information, you can visit  http://www.creative-proteomics.com/Services/Label-free-quantification.htm.
About Creative Proteomics
Creative Proteomics specializes in a full range of services to support various proteome-related researches from identification of single proteins to large-scale proteomic studies. We have one of the most advanced proteomics platforms in the world and our staff scientists are experienced proteomics professionals. Our proteome analysis platform provides protein separation, characterization, identification and quantification services, featured with high throughput and super-sensitivity. In addition, analyses of protein post-translational modifications such as phosphorylation and glycosylation are available.
Contact Creative Proteomics
Address: 45-16 Ramsey Road, Shirley, NY 11967, USA
Tel: 1-631-624-4882
Email: info@creative-proteomics.com

Visit More Blogs at: Mass Spectrometry For Proteins

Friday, 13 March 2015

Mass Spectrometry in Protein Identification





It has been widely acknowledged that proteins, large molecules, can direct our body activities, organize our thoughts, and defend us against infection, thus keeps us healthy. But if there occurs mutation, proteins can aslo make us in trouble and even threaten our life.
Proteomics is the study of the structure and function of proteins. And quantitative proteomics involves identification and quantification of proteins in various biological systems. On the one hand, protein quantification determines the total protein concentration in a sample; on the other hand, protein identification helps scientists to know better the structure and type of certain proteins.
During the last two decades, mass spectrometry has become a primary method for protein identification from complex mixtures of biological origin. But the questions is how can it help protein identification? After doing a research, the writer found that it indeed helps protein identification in a couple of ways:
Firstly, it can do help in the identification of protein binding partners that is to say mass spectrometry can help identify the specific proteome for protein interactions
Secondly, it can help to characterize the purified protein samples: with mass spectrometry, the right sequences can be ensured and the right location for the modification can be guaranteed. Furthermore, it can also do some help in the identification of impurities in the preparation.
Thirdly, it can help work out protein post translational modification; with the help of it, you can identify any modifications in the preparation.
To name a few...
Since the profound meaning of protein identification in the study of proteins, there are a bunch of biotech companies worldwide that are offering protein identification services. Creative Proteomics is an excellent one among them. Current protein identification service in Creative Proteomics includes: Digestion (in-gel or in solution), Molecular Weight Determination and Molecular Weight Distribution of Peptides or Proteins, Sample Preparation, Purity Analysis of Peptides or Proteins, Peptide Mass Fingerprinting (PMF), Sequence Analysis of Peptides or Proteins (N-, C-), De Novo Protein Sequence Analysis, Accurate Mass Determination, Shotgun Protein Identification, Membrane Proteomics and Subcellular Proteomics.
About Creative Proteomics
Creative Proteomics specializes in a full range of services to support various proteome-related researches from identification of single proteins to large-scale proteomic studies. We have one of the most advanced proteomics platforms in the world and our staff scientists are experienced proteomics professionals. Our proteome analysis platform provides protein separation, characterization, identification and quantification services, featured with high throughput and super-sensitivity. In addition, analyses of protein post-translational modifications such as phosphorylation and glycosylation are available.
Contact Creative Proteomics
Address: 45-16 Ramsey Road, Shirley, NY 11967, USA
Tel: 1-631-624-4882
Email: info@creative-proteomics.com

Visit More Blogs at:  Protein Identification Service