Welcome to AB Biosciences

In Vivo vs. In Vitro

News Update. January 1, 2021

Armed with decades of experience in protein engineering and mammalian expression of recombinant biologics, ABB has engineered and produced a large panel of reagents biologics that are the best commercially available. All protein products are affinity purified from cultured media of human embryonic kidney (HEK) 293 cells or Chinese hamster (CHO) cells, size fractionated, buffer-exchanged into PBS, and stored at -80°C. The activity of each protein is validated by ELISA or FACS for the respective ligand/receptor interaction. All proteins are produced at the AB Biosciences’ protein lab with meticulous quality control. These affinity-purified, SEC sized protein reagents are excellent tools for most biomedical applications. In addition, AB Biosciences also offers proteins with very low endotoxin content (≤ 1.0 EU/mg protein) that is 1000-fold less than most of other low endotoxin protein reagents commercially available. As such our low endotoxin reagents are suited for many applications including in vivo uses for animal studies without the complications associated with the inflammatory reactions triggered by endotoxin.

  To distinguish these two reagent classes, proteins for general in vitro applications are given a single code “-G” at the end of the product code. Similarly, proteins with low endotoxin contents for in vivo uses have product codes end with “-V”. For example, PZHU005-G is Z-MAB of Human IgG1 isotype that was affinity-purified, SEC sized and suited for in vitro applications; and PZHU005-V is the same antibody with low endotoxin content and is suited for in vivo applications including animal studies. Please also see the table below for characteristics of these two protein reagent classes.

Characteristics Application
In vitro (G class) In vivo (V class)
Recombinantly engineered + +
Produced in mammalian cells + +
Affinity purified  + +
Properly sized by SEC + +
Native protein conformation + +
Physiological buffer system + +
No preservatives added + +
> 95% purity (by SDS-PAGE) + +
≤ 1 EU endotoxin per mg protein
Suitable for animal studies