Distinguishing between Isoleucine and Leucine

Isoleucine (Ile, I) and leucine (Leu, L) are isobaric residues or amino acids with the same mass (Figure 1). Conventional mass spectrometry-based proteomics cannot be easily used to distinguish between Ile and Leu. In 2016, Rapid Novor became the first to commerc­­ially introduce a service, w-ion isoleucine-leucine determination (WILD® ), to distinguish between Ile and [...]

2020-01-07T16:16:17-05:00January 7th, 2020|Blog, FAQ|0 Comments

How Mass Spectrometry Can Help Limit Reproducibility Problems

How much time is spent trying to find the right antibody? Photo Credit: María Rosales Gerpe Reproduced from Rosales Gerpe, M., Barber J., (Nov 8, 2019). How Mass Spectrometry Can Help Limit Reproducibility Problems. Scientific American, a Division of Springer Nature America, Inc., with permission.  Antibodies are critical for biological and medical [...]

2019-11-13T11:12:01-05:00November 13th, 2019|Blog|0 Comments

Antibody Species Q&A

Q: What antibody species can you sequence? A: All of them! We are able to sequence any species because we use de novo protein sequencing by tandem mass spectrometry (MS/MS). This type of protein sequencing by mass spectrometry does not rely on existing databases that might introduce bias or wrong amino acid calls [1]. In [...]

2019-08-26T10:43:47-04:00August 26th, 2019|Blog, FAQ|0 Comments

Shipping Conditions Q&A

Q: Under what shipping conditions should I send my protein sample? A: We suggest the following shipping conditions: We recommend that you ship your samples either lyophilized or in solution. If your samples are already lyophilized it is best to ship them to us in that form, they can be shipped at ambient temperatures, [...]

2019-08-26T09:34:37-04:00August 19th, 2019|Blog, FAQ|0 Comments

Protein Purity Q&A

Q: How much protein and what purity is needed for protein sequencing? A: We typically accept samples at 100 µg with at least 80% purity, rare in the field. To measure the amount of protein, you can use a microvolume spectrophotometer such as the Nanodrop or a traditional Bradford assay. To assess purity of [...]

2019-08-15T16:19:55-04:00August 12th, 2019|Blog|0 Comments

Protein Contaminants Q&A

Q: What are common contaminants that could affect my protein sequencing results? A: Typical contaminants that we see affecting samples are non-target proteins, and non-target antibodies [1, 2, 3]. Protein Contaminants The most common protein contaminants include keratin and serum albumin [1, 2, 3]. Other Mass Spectrometry (MS) protein contaminants identified in research labs worldwide [...]

2019-08-12T14:54:06-04:00August 5th, 2019|Blog|0 Comments

What is Protein Sequencing by Mass Spectrometry?

Frederick Sanger, father of DNA sequencing, sequenced the first protein, insulin, before he began his efforts in deciphering nucleotide codes. Nowadays, DNA sequencing is so popular that it is easy to forget that the first sequenced biological material was protein – insulin, by Sanger [1, 2]. Sanger, and another [...]

2019-08-12T14:40:37-04:00August 2nd, 2019|Blog|0 Comments

Milestone: 1000 Projects

Meet Anthony: he likes having a quality meal. Balanced. With healthy fats like avocado. Anthony wakes up every morning to the smell of coffee and a strong sense of carpe diem. He doesn’t just employ the art of positive visualization, popularized by The Sopranos. His dogma, if a TV show’s principles could be dogma, is [...]

2019-07-31T16:13:57-04:00July 29th, 2019|Blog|0 Comments

Highlights from ASMS 2019

This year’s American Society for Mass Spectrometry (ASMS) conference took place in Atlanta, Georgia, the peach state of the US. Our Proteomics Specialist, Kathleen Gorospe, brought back home some delicious peach cookies, for which we have no pictures because they were devoured instantly. The ASMS conference was very fruitful indeed. There was a total of [...]

2019-08-09T11:09:30-04:00July 17th, 2019|Blog|0 Comments