Immune Checkpoint Proteins

Protectants (stabilizers) are added to protect proteins during lyophilization and/or long-term storage. Proteins are subjected to various stresses generated by lyophilization which may cause loss of activity, aggregation, or denaturation. Protectants can alleviate the stresses by several mechanisms including formation of an amorphous glassy state, replacing water, hydrogen bonding to proteins, physical dilution and separation of protein molecules, etc. Common protectants/stabilizers include sugars, polyols, polymers, surfactants, as well as some proteins and amino acids. We use trehalose and mannitol (normally 8% w/v) as protectants for lyophilization. Trehalose is a non-reducing disaccharide, well-known for its ability to stabilize biomolecules and microorganisms during prolonged period of desiccation. Mannitol is also commonly used as a stabilizer as well as a bulking agent in the process of lyophilization. It was reported to reduce aggregation for some proteins during lyophilization.

Immune Checkpoint Protein Strengths

• Validated bioactivity & High purity (SDS-PAGE); • His-tagged, Fc-tagged and tag free proteins
• Mutiple species: Human, Mouse, Canine, Rat, Rhesus,Cynomolgus; • Endotoxin less than 1EU/μg by the LAL method.
• Produced in house & Animal free  
Fig .1 The purity of PD-L1 protein (10084-H02H) was >95% as determined by SDS-PAGE. Fig .2 The activity assay (ED50=59.8 ng/mL) of CD27 protein (10039-H03H)by binding to CD70 Protein.

Immune Checkpoint Protein Strengths

Sino Biological Inc. has researched and developed proteins for almost 50 immune checkpoints as shown below. Recombinant immune checkpoint proteins cover multiple species and various tags. Binding activity has also been assayed and confirmed. All the proteins can be customed. If you cann't find a desired one, please contact

Immune Checkpoint Information