Studies on precipitation and turbidimetric methods for fibrinogen determination employing Na2SO3, Na2SO4, (NH4) 2S04 and a mixture of phosphate salts are presented. Optimal reaction conditions for these technics have been verified. The amounts of plasma fibrinogen precipitated by the sulfite and phosphate methods are in closer agreement than either are with values obtained by the (NH4)2S04 and ...

To reduce the effects of extraneous potentials caused by muscle tremor, sweating, and interference from power circuits, it is desirable to restrict the frequency range of the cathode ray vectorcardiograph. Mathematical analysis of idealized waves and experiments with a photoelectric electrocardiographic generator indicate that a frequency range between the half-power frequency of 0.8 to 80 cycl...

HE STUDY OF CATALASE ACTIVITY has been the subject of much investigation and has necessitated the use of very elegant technics. Recently, methods have been introduced which simplified the technics for estimating catalase activity. Among these are the iodimetric titration procedure of Dille and Watkins (1), the use of sodium perborate as a source of hydrogen peroxide (2), and various methods uti...

Historical Review The use of isotopes in clinical cardiology was introduced by Blumgart, Yens, and Weiss, who used radium C and a cloud chamber to estimate the linear velocity of blood flow in an extensive series of studies starting in 1927.1, 2 Undoubtedly the major stimulus to the adoption of tracer technics came from the introduction of man-made radioisotopes after World War II. During the i...

‘]TI-IE USE of the Natelsoit microgasometer (1-3), has now become firmly established in many routine clinical laboratories. As with most clinical technics, it is amenable to modification resulting in greater simplification, ease of operation, and facility of analysis. It must be stated parenthetically, however, that this does not diminish the accuracy of the original method (1). This paper desc...

ABIOUS TECHNICS HAVE BEEN EMPLOYED in observing the end points in performing prothrombin determinations. Some of these entail the use of wire loops (1), direct visual observation of the clot (2), and use of densitometers (3). In our laboratories we have adopted the method of Quick (2). We have found that with the aid of an improvised viewer, observations of any physical clot can be studied and ...