[Accelerated measurement of the volume of condensed chromatin from electron microscopic photographs].

The fraction of condensed chromatin (C. C., %) in cell nuclei images was determined by the aid of the "random step grid". 100 random points were thrown on every electron microscopic images. The number of points in C. C. images was counted. Lymphocyte nuclei in spleen and lymph nodes of normal cows have a higher content of C. C. (61 +/- 1.6%) Than those of cows suffering from lympholeucosis in haematological (49 +/- 21%) and in tumor (44 +/- 1.1%) stages. The counting procedure takes about 2 hours for 90 images. The random step grid can be easily available in every day practice.