Published in: Proceedings of the National Academy of Sciences, U.S. vol. 46, No. 4, pp. 439-440 (April, 1960):

"Metabolism and Morphology of Ribonucleoprotein Particles from the Cell Nucleus of Lymphocytes".

John H. Frenster, Vincent G. Allfrey, and Alfred E. Mirsky
Rockefeller University, New York, N.Y. 10021

Figures 5a (left) and 5b (right).
Fig. 5a. - Isolated whole nucleus before buffer extraction. X 15,000.
Fig. 5b. - Nucleolar region of nucleus in Fig. 5a. X 240,000.

Figures 5c (left) and 6 (right).
Fig. 5c. - Chromosomal region of nucleus in Fig. 5a. X 240,000.
Fig. 6. - Isolated residual nucleus after buffer extraction. X 15,000.

Figures 7a (left) and 7b (right).
Fig. 7a. - Particles 700-2,000 S of first Tris extract. X 60,000.
Fig. 7b. - Particles 700-2,000 S of the first Tris extract. X 240,000.

Figures 8a (left) and 8b (right).
Fig. 8a. - Particles of the third Tris extract. X 240,000.
Fig. 8b. - Particles of the third Tris extract. X 240,000.