A major technical difficulty in the Treponema pallidum immobilization (TPI) test developed by Nelson and Mayer (1949) is the failure of their suspending medium to maintain consistently uniform survival of virulent T. pallidum employed as the antigen. For this reason, early studies to show that the sensitivity of the test may be increased by decreasing the concentration of spirochaetes resulted ...

1. The respiration of the reticulocytes of the rabbit has been measured during the period of an anemia produced by phenylhydrazine. Though the respiration increased greatly during the phase of regeneration, the oxygen consumption per billion reticulocytes throughout the period remained approximately the same. 2. The respiration of the reticulocytes was affected by changes in the reaction of the...

A modified sporulation medium for Clostridium perfringens was formulated in which a larger number of spores were produced than in SEC broth and in which spores of greater heat resistance were produced than in Ellner's medium when it was also used as the suspending medium. This modified medium consisted of 1.5% peptone; 3.0% Trypticase; 0.4% starch; 0.5% NaCl; and 0.02% MgSO(4). The addition of ...

the freeze-drying process. Continued viability of rehydrated cells during incubation at 37 C for 3 hours was dependent on the composition of the suspending medium. The number of viable organisms decreased greatly when suspended and incubated in water. Several salts were effective in maintaining higher viable cell counts. Maximum recovery of viable cells of one dried preparation rehydrated in ma...

A totally revised crossmatching and antibody screening procedure has been designed using low ionic strength saline as the suspending medium for red cells in the saline and enzyme phases as well as the antiglobulin test. The replacement of Pasteur pipettes with precision samplers for all serum and red cell dispensing has resulted in improvement in the reproducibility and standardisation of techn...

Yeast cells suspended in distilled water, when damaged by prolonged sublethal dosages of ultraviolet radiation, liberate substances into the suspending medium capable of producing marked proliferation of normal yeast cells (1). This effect is encountered without appreciable killing of the irradiated cells. Previous communications have presented evidence that members of the vitamin B complex and...

Catalase present in the suspending medium during irradiation significantly reduced the lethal action of gamma radiation from cobalt6O for anaerobic bacterial spores. This finding supports the theory that the lethal action of ionizing radiations is at least partially due to secondary effects of the irradiation. Furthermore, such protection of anaerobic bacterial spores is important when steriliz...

Hemoglobin Setif produces pseudosickling of red cells in vitro; the nature of the process and the conditions that “trigger” it are unknown. Studies of red cells. hemolysates. purified hemoglobin solutions, and artificial mixtures of Hb A and Setif suggest that pseudosickling is produced by intracellular crystallization of insoluble hemoglobin. Increased tonicity of the suspending medium accentu...