An Apparatus for Vacuum Drying in the Frozen State

Rapid Total Extraction of Auxin from Green Plant Tissue

“…South Haven) as giving auxin yields of at least 20 million TDC per gram dry weight of tissue (1 N NaOH, 60 minutes at 1200C.). Link, Eggers and Moulton (1940) report that the auxin in ether extracts of cabbage is resistant to acid and alkali, but since none of their data (table 4 of their paper) on this point are significant, i.e., no Avena curvatures are in the proportionality range, their evidence is insufficient for this conclusion.…”

“…Within the past three to five years, however, increasing difficulties have been encountered with this procedure, at least with many tissues. Thus Thimann and Skoog (1940), Gustafson (1940), Link et al (1940), and others have found that some green tissues, if allowed to remain in ether, continue to yield auxin slowly over long periods of time, even as much as one year. Obviously in these cases the use of ether as an auxin extracting agent is wholly inadequate.…”

“…These extraordinary yields are the highest so far reported in the literature. Link, Eggers and Moulton (1940) report an auxin yield obtained by ether extraction from cabbage equivalent to about 45 micrograms of indoleacetic acid per gram dry weight (4.5 million TDC), but this required 22 hours extraction.…”

Osmotic Pressure Determinations With Isolated Protoplasmic Proteins

“…Since FLOSDORF and MUDD'S (2) original work, many modifications of the "lyophile apparatus" have been described (1,5,8,10,12). The commercial "cryoscopic dryers" avoid the need of dry ice (except for preliminary freezing) by using a desiccant that can be regenerated.…”