Effect of donor age on long-term culture of bone marrow in vitro.

Previous reports suggest that 33 degrees C is the optimum temperature for the long-term culture of murine bone marrow in vitro. We found that horse serum was an important variable determining our ability to culture marrow from immature (less than 10 weeks) mice at 37 degrees C. While some batches supported growth others did not. The ability of deficient horse serum to support growth could be corrected if the culture was fed at mid-week with additional medium. Marrow from aged mice (96 weeks and older) could invariably be cultured at 37 degrees C irrespective of the horse serum batch used for culture. Adult mice (20-24 weeks) gave intermediate results between immature and aged mice. All three groups of mice studied could be cultured at 33 degrees C irrespective of the batch of horse serum used or the age of the donor. These results indicate that horse serum provides a factor(s) which varies in concentration from batch to batch and is essential for normal marrow growth in vitro. The requirement for this factor is greater at higher temperature and in younger animals. Marrow from adult and aged mice was then simultaneously cultured at 33 degrees C and 37 degrees C. For adult mice the cell recovery at 33 degrees C was initially significantly higher than at 37 degrees C but at later times became less. As a result cumulative recovery at both temperatures was equal. Cumulative cell recovery and culture survival time was significantly less in the aged than the young mice cultures.(ABSTRACT TRUNCATED AT 250 WORDS)