Intralaboratory quality control of hematology. Comparison of two systems.

Two systems for quality control have been compared, viz., the whole-blood control preparation method and the algorithm method using the geometric moving average XB and a new estimator Y. The system involving whole-blood controls has the advantage of simplicity of operation, but the economic cost of commercial preparations is often high. The algorith system has the advantage that results of all the test samples are used in the calculation; to some extent, this provides a buffer against random variation. The number of count-outs in a given channel is related to the precision of the channel, which in turn is a function of the number of determinations and calculations required for that result. An error of around 1% is introduced into the result each time a calculation is performed. A successful quality control scheme should contain elements of both control preparation and algorithm methods.

Processing haematological data on a dedicated computer.

A system of processing the laboratory data of a busy haematology department serving a teaching group of hospitals and the general practitioners of the district is described. The system, which has been in routine use for over two years, is based on a dedicated CTL8030 computer sited in the laboratory utilising Lynwood visual display units (VDUs) for both input and access to the data files. Data from the Coulter 'S' is fed by an interface to the computer and to other data handling modules. Manual test results are entered via VDUs, mainly by laboratory staff who also validate all data. Access is available to all data for answering telephone requests. Data are retained on the disc file for 48 hours only, and cumulative reporting was not planned into the system as deliberate policy. Quality control of the Coulter 'S' output is maintained both throughout the day and retrospectively at the end of each working day using both whole blood patient blood transfusion profiles, a record of blood and product usage, worksheets, quality control information, end-of-day listing in alphabetical order plus statistical information for administrative purposes. Since its introduction the system has been remarkably free from breakdown as a result of hardware failure. A number of fail safe/fallbacks have been included in the system.

Oxygen-pulse curves in rat liver mitochondrial suspensions. Some observations and deductions.

1. The inference, implicit in the chemiosmotic hypothesis, that protons move into the bulk phase during ATP synthesis was investigated. 2. Incubation of rat liver mitochondria in the presence of the cation exchanger CM-Sephadex C-50 caused alkalinization in the medium, though total ATP synthesis remained unchanged. The addition of N-ethylmaleimide prevented the alkalinization, but there was still no indication of protons passing into the medium. The expected proton movement [Mitchell & Moyle (1967) Biochem. J. 105, 1147--1162] was readily detected when as an equivalent acid pulse. 3. Analysis of delta H+ decay curves after O2 pulses (3 micrograms-atoms of O/g of protein) indicated the presence of fast and slow components of decay, with first-order rate constants (k) of 0.24s-1 and 0.032s-1. The fast decay was finite and was eliminated in the presence of N-ethylmaleimide. 4. These observations are interpreted as evidence for the development of unmasking of fixed charges on the outer surface of the mitochondrial inner membrane during energization and for the existence of proton-retentive electrical fields (rho-zones) on this surface. The charge concentration is calculated as about 1 charge/10nm2. 5. A cycle of changes in a single fixed-charge molecule is proposed which mediates both Ca2+ uptake and the first step in the utilization of the rho-zone protonmotive force, delta p rho.