A new and simplified procedure for the automated determination of serum alkaline phosphatase uses the AutoAnalyzer. The substrate p-nitrophenylphosphate in 2amino-2-methyl-l-propanol offers the prime advantage of providing directly its own chromogen, p-nitrophenol, following enzyme action. The procedure also permits use of small sample volumes, provides linear reaction rates, and has a simple m...

In connection with other studies in this laboratory (1, 2),’ it became necessary to determine the concentration of urea in the blood of individual new-born rats. In view of the small quantities of blood available and the need for a considerable number of analyses, the calorimetric method developed by Archibald (3) appeared to be particularly suitable. This method is based upon the formation of ...

A new colorimetric micromethod for the estimation of y-glutamyl transpeptidase activity has been developed, in order to obtain more reliable results with greater ease on smaller samples of a wider variety. Enzyme activity can be determined on 0.1 m/ of serum or less, or the equivalent of spinal fluid or tissue extracts, because the precipitation of proteins has been omitted. Therefore, correcti...

Improvements in the Zimmermann reaction are effected by using methanol as a solvent for the reagents employed in the reaction in place of ethanol or aqueous ethanol. The advantages are as follows. Considerably lower blanks are obtained; extraneous chromogens are negligible at the wavelength of measurement, so that no correction procedure or extraction process is required; high concentrations of...

The method in which thiobarbituric acid is used for sialic acid determination was adapted to a fully automated procedure, in which the chromogen need not be extracted with an organic solvent. The entire procedure, including hydrolysis, requires 35 mm and 25 l of serum for one analysis, but 30 samples can be analyzed per hour. The procedure, slightly modified, can be used to measure as little as...

Ascending projections to the thalamus from a midbrain somatosensory area were investigated in a reptile, Caiman crocodilus. Connections were determined utilizing horseradish peroxidase (HRP) neurohistochemistry in which tetramethylbenzidine was the chromogen. Anterograde experiments, in which HRP injections were placed into the midbrain, revealed bilateral projections to the medialis complex of...

The available methods for double-labeling preembedding immunoelectron microscopy are highly limited because not only should the ultrastructure be preserved, but also the different antigens should be visualized by reaction end products that can be clearly distinguished in gray-scale images. In these procedures, one antigen is detected with 3,3'-diaminobenzidine (DAB) chromogen, resulting in a ho...

Since agreement was reached about a correlation between the output of estrogen on the one hand and placental functions and foetal viability on the other (VIDETZKY, 1965 and JAFFE and LEVITZ, 1967), numerous investigations have been published on the determination of the three classic estrogens, estrone, estradiol and estriol, in the urine of mammals. In farm animals the amount of urinary pigment...

A modification of the Fischl (6) glyoxylic acid method for tryptophan was developed which permits the reaction to occur quantitatively in aqueous solution by substitution of 70% HCIO4 (w/v) for concentrated H2S04. Spectral analysis of the chromogen formed showed a strong adsorption band at 365 m1 for pure tryptophan which was 17 times more sensitive than that at 560 mit. Factors were studied wh...