The sequence of the first five N-terminal amino acids was determined and was found to be Ala-Leu-Pro-Ile-Cys.
The ED50 as determined by the dose-dependant stimulation of the proliferation of rat lymphoma, Nb2-11 was found to be < 0.065ng/ml concentration corresponding to a Specific Activity of 15.4MIU/mg.
The protein was lyophilized from a concentrated (1mg/ml) solution with 0.0045mM NaHCO3.
Sterile Filtered White lyophilized (freeze-dried) powder.
Protein quantitation was carried out by two independent methods:
1. UV spectroscopy at 280 nm using the absorbency value of 0.87 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 calibrated solution of Prolactinl as a Reference Standard.
Greater than 98.0% as determined by:
(a) Analysis by SEC-HPLC.
(b) Analysis by SDS-PAGE.
It is recommended to reconstitute the lyophilized Prolactin in sterile 18MΩ-cm H2O not less than 100ug/ml, which can then be further diluted to other aqueous solutions.
Lyophilized Prolactin although stable at room temperature for 3 weeks, should be stored desiccated below -18oC. Upon reconstitution Prl should be stored at 4oC between 2-7 days and for future use below -18oC.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Please prevent freeze-thaw cycles.
Mammotropin, Luteotropic hormone, Luteotropin, PRL.
