Fractionation of embryo extract by ultracentrifugation. I. Analysis of fractions,

✍ Scribed by Wolken, Jerome J.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1952
• Tongue: English
• Weight: 501 KB
• Volume: 40
• Category: Article
• ISSN: 0095-9898
• DOI: 10.1002/jcp.1030400206

✦ Synopsis

Since the early Jvork of Carrel ( '21) and his collaborators, who demonstrated the growth-promoting activity of chicken emloryo extract, attempts have been made to further isolate and characterize the components responsible f o r this growth stimulation (Fischer, '46). Later, Claude ( '38) isolated by differeiitial centrifugation a fraction from normal embryonic tissue rich in nucleic acid, and Tennent, Leibow, and Stern ('41) showed that a similar fraction isolated from chicken embryo extract accelerated the growth of mouse heart fibroblasts in tissue culture. But Claude ('49)' Fischer ('46)' Brachet ('43, '45) and others showed that this growth-stimulating effect was present in the supernatant fluid as well.

Previous growth studies by Wollren ('48, '50) on the incorporation of P32 into the developing embryo suggested a tracer method as a n aid in fractionation and analysis. The experimental procedures which follow are an attempt to isolate by differential centrifugation tagged fractions which may be tested for their growth-stimulating effect, and to further characterize them as to their chemical nature and physicdl properties, such as sedimentation constant, size, shape, and homogeneity.