PT  - JOURNAL ARTICLE
AU  - Wilbur, D. Scott
AU  - Hamlin, Donald
AU  - Chyan, Ming-Kuan
AU  - Sandmaier, Brenda
TI  - Isolation and protein labeling of At-211 from irradiated bismuth targets using a modified wet chemistry approach
DP  - 2009 May 01
TA  - Journal of Nuclear Medicine
PG  - 99--99
VI  - 50
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/50/supplement_2/99.short
4100  - http://jnm.snmjournals.org/content/50/supplement_2/99.full
SO  - J Nucl Med2009 May 01; 50
AB  - 99 Objectives The objectives were to improve consistency and yields of 211At isolated from irradiated targets using a modified wet chemistry approach, and to demonstrate protein labeling. Methods The large quantity of Bi metal used in our irradiations required modification of the literature reports for wet chemistry isolation of 211At. Bi metal was dissolved in a minimum amount of HNO3 (15mL with rinse). The HNO3 was removed by distillation. The residue was dissolved in 8M HCl and transferred to another vial (10 mL HCl with rinse). The HCl solution was extracted with diisopropyl ether (DIPE; 8mL)-rinsed with 8M HCl (3mL). Two mL of 4N NaOH was added to the DIPE layer. The NaOH layer was separated and the DIPE was rinsed with 0.5mL H2O. The volume of the NaOH solution was reduced by distillation. To the residue was added 1mL of H2O. The resultant aqueous 211At solution was brought to near neutral with 8N HCl (slightly basic). The 211At was reacted with chloramine-T to label antibodies conjugated with a closo-decaborate(2-) derivative. Results Isolation of the 211At was accomplished in ~80% recovery (decay corrected) from the wet chemistry process. The overall time was approximately 2.5 h from dissolution of target to obtaining labeled MAbs. Labeled MAbs were obtained in 66-71% yield after purification. Conclusions The modified wet chemistry isolation approach provides more consistent and higher recovery yields than the dry distillation approach. Further optimization of recovery yields and minimization of time required is on-going. Research Support These studies were supported by grants from the National Institutes of Health (CA118940 and CA113431).