| Activity |  | Biological Activity is evidenced by inducing proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor | 
| Appearance |  | Sterile Filtered White lyophilized (freeze-dried) powder | 
| Formulation |  | The protein was lyophilized from a concentrated (1mg/ml) solution with 0.0045mM NaHCO3 | 
| Purity |  | > 95.0% (a) by SEC-HPLC; (b) by SDS-PAGE | 
| Solubility |  | The lyophilized Leptin is very soluble inwater and most aqueous buffers below and above the isoelectric point | 
| Amino Acid Analysis |  | The sequence of the first five N-terminalamino acids was determined and was found to be Ala-Val-Pro-Ile-Gln | 
| Protein Content |  | Protein quantitation was carried out by twoindependent methods:1.UV spectroscopy at 280 nm using theabsorbency value of 0.878 as the extinction coefficient for a 0.1% (1mg/ml)solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics).2.Analysis by RP-HPLC, using a calibratedsolution of Leptin as a Reference Standard. |