Growth kinetics by scanning of granulocytic cell colonies in glass capillaries

Pure granulocytic colonies were cultivated from mouse bone marrow cells in agar contained in glass capillary tubes using mouse embryo conditioned medium as colony stimulating activity. A random distribution of colonies along the agar gels was achieved under controlled conditions. Only 3 capillaries were needed for a coefficient of variation around 5% provided at least 104 cells were seeded per capillary. The daily growth of single colonies within an agar capillary was followed, using the light scattering properties of the colonies for automatic scanning. The position of the colonies in the capillary greatly affected the scan signal; the consequences of positional changes were studied in detail. Using the mean peak height as growth parameter, the onset of measureable granulocytic colony growth was found between day 2 and 3, the maximum colony size was reached between day 7 and 9, after which the colonies decayed. Other parameters such as colony count and total peak are were determined and their sinificance discussed.