Automated method for the determination of phenol in biological products

A method is described for the rapid and accurate determination of phenol in biological products by using automated methods.

Automated method for the determination of free formalin in biological products

A method is described for the rapid and accurate determination of free Formalin in biological products.

A simple method for measuring a picogram of acetylcholine using the clam (Mya arenaria) heart

1. A simple and reliable method is described for assaying 1 pg or less of acetylcholine (ACh) using a strip of clam (Mya arenaria) heart.2. Clam heart preparations generally are extremely selective for ACh. The preparation described is at least 10(5) times less sensitive to the following: acetyl coenzyme A, adrenaline, choline, dopamine, gamma-aminobutyric acid, glutamic acid, histamine, 5-hydroxytryptamine and noradrenaline.3. Because this preparation is one of the most sensitive known for detecting ACh, it should prove useful for assaying particularly low levels of this substance in biological extracts.

Evidence for a second chemotactic system in the cellular slime mold, Dictyostelium discoideum

An unknown substance found in bacteria (Escherichia coli) is especially effective in attracting the vegetative amoebae of the cellular slime mold, Dictyostelium discoideum. However, the aggregating amoebae are not attracted to it at all. On the other hand, the vegetative amoebae show very little chemotactic response to cyclic adenosine monophosphate (cyclic AMP), whereas the aggregating amoebae are exceptionally responsive to it. It is suggested that the new factor may be used in food seeking, whereas cyclic AMP, the chemotactic substance responsible for aggregation, is the acrasin of this species. The important point is that the amoebae are differentially stage-specific in their responses to these two chemotactic agents.

Adenosine-3',5'-phosphate: identification as acrasin in a species of cellular slime mold

Acrasin, the chemotactic agent responsible for aggregation in thecellular slime molds, has been identified for one species, Dictyostelium discoideum, as adenosine-3', 5'-phosphate.