The status of automation and data processing in the United States blood banking community.

A survey of the extent of automation and data processing in the blood banking community was conducted by questionnaire. The likelihood that a facility had some type of automation was related to the volume of blood products produced or transfused. Facilitates that collected blood or collected and transfused blood were more likely to have automation for ABO and Rh testing than those that only transfused blood. Automation for many other blood bank tests is unavailable. Many facilities had data processing capability, which is used primarily for accounting.

A robotic system to prepare samples for HTLV-III testing.

A robotic handling system was adapted to perform the sampling and dilution steps needed in an assay to detect antibodies to the HTLV-III virus, the causative agent of AIDS. The system reduced the labor required to prepare the samples and provided standardization and accuracy in the preparation of the samples.

Complement activation in semi-solid medium: Insolubilization of properdin and the third component of complement (C3) in agar gels.

Although the role of properdin in the alternative pathway of complement activation remains unclear, evidence has recently been obtained for the formation of complexes between properdin and other components, including C3. In this study such complexes have apparently been directly visualized. When normal human serum and properdin were allowed to diffuse toward each other in agar gel for 16 hr, a line of precipitation could be seen when stained with Coomassie brilliant blue. The reaction occured at pH 8.6 in 0.05 M Veronal buffer at room temperature but not under physiologic conditions of pH or tonicity. Like the alternative pathway, the reaction was Me++ dependent, occurred with C2- or C5-deficient or hypogammaglobulinemic serum, and did not occur with aged, 52 degrees C-inactivated, C3b inactivator-deficient, or C3-deficient serum. 125I-labeled C3 and properdin but not Factor B were incorporated in the precipitate. Eleven sera containing the C3 nephritic factor failed to produce a precipitate with properdin, but a line of precipitation occurred between seven of these sera and normal serum. This line showed identity with the line occurring between properdin and normal serum. The phenomenon appears to result from formation of insoluble complexes between proteins of the alternative pathway and agar.

The relationship of glycine-rich -glycoprotein to factor B in the properdin system and to the cobra factor-binding protein of huan serum.

Factor B activity of the properdin system was found to be identical with purified glycine-rich beta-glycoprotein (GBG) but was distinct from the normal human serum protein capable of forming a C3-inactivating complex with a protein from cobra venom (CoF). Factor B activity coincided with electrophoretically separated GBG genetic variants, whereas the CoF-binding protein did not. GBGase destroyed factor B as it cleaved GBG but did not destroy the C3-inactivating activity of the CoF-binding protein. During incubation of serum with CoF, GBG did not change in molecular size, nor was there any coincidence in the immunoelectrophoretic mobilities of CoF and GBG. It was not possible to precipitate labeled CoF incubated with serum by anti-GBG, nor labeled GBG from serum incubated with CoF by anti-CoF. The CoF-binding capacity of serum was 2 mg/100 ml or less or under 6.5% of the serum concentration of GBG. When labeled CoF was added to serum below the binding capacity, complete complexation of the CoF was demonstrated, whereas CoF was largely uncomplexed when CoF was added in amounts equimolar to GBG.