Why is my protein’s N-terminal blocked (and what can I do about it)?
Question: Does a blocked N-terminal hinder Edman degradation? I found that the N-terminal of my protein is blocked. So, how can I...
Why you need accurate concentration determination of protein standards
Question: How do I quantify my protein standard? How do I quantify my protein standard? Is it true that it if it...
Determine the Molar Extinction Coefficient of protein in 3 small steps
Question: How do I determine the molar extinction coefficient of my protein? I have a purified protein that I would like to...
4 things to remember about Amino Acid Analysis of proteins & peptides
Why perform Amino Acid Analysis? Amino acid analysis of proteins is a method to determine the absolute amounts of individual amino...
1D SDS PAGE versus 2D PAGE. Any recommendations?
Question: Should I use 1D or 2D SDS PAGE? I’m interested in isolating and identifying cell surface receptor proteins. They typically have high...
How much protein should I load for protein identification by mass spec
Question: How should I prepare my samples for 2D electrophoresis? How should I prepare my samples for 2D electrophoresis, and how much...
Common protein contaminants in mass spectrometric protein ID
Questions: Why was Keratin identified in my 1D gel band? Is the keratin determined by the protein identification service in my...
Useful Protein Molecular Weight Calculator kDa
Protein molecular weight calculator kDa The rule of thumb for conversion of microgram amounts into picomole amounts at different protein molecular...
What does the Mascot Score mean?
Question: What does the Mascot Score mean? I just got my protein identification report. What does the Mascot Score mean? Answer: The Protein Identification...
Protocol for gel silver staining – mass spec & protein identification
Problems arising from using commercial staining kits: Scientists use silver staining for sensitive detection of proteins separated by 1D and 2D...
Preparing samples for N- and C-terminal sequencing by MALDI ISD
Question: How do I prepare samples for MALDI ISD analysis? I am interested in your N and C-terminal sequencing using MALDI ISD....
Optimize PVDF membrane electroblotting for N-terminal Edman sequencing
Question: How do I optimize electroblotting conditions onto a PVDF membrane? Our 12 kDa protein separates well on 1D SDS PAGE but...
Host Cell Protein monitoring in process development – using mass spec
Mass spectrometry based Host Cell Protein identification and quantification The Mass Spec Host Cell Protein (HCP) assay is applied for monitoring...