Rapid and inexpensive blood typing on thermoplastic chips.

A portable and cost-effective colorimetric diagnostic device was fabricated for rapid ABO and Rh blood typing. Using microfluidic construction on a thermoplastic chip, blood antibodies were preloaded into a reaction channel and exposed to blood samples to initiate a haemagglutination reaction. Downstream high-aspect ratio filters, composed of 2 µm high microslits, block agglutinated red blood cells (RBCs) to turn the reaction channel red, indicating the presence of the corresponding blood antigen. Users manually actuate the blood sample using a simple screw pump that drives the solution through serpentine reaction channels and chaotic micromixers for maximum interaction of the preloaded antibodies with the blood sample antigens. Mismatched RBCs and antibodies elute from the channel into an outlet reservoir based on the rheological properties of RBCs with no colorimetric change. As a result, unambiguous blood typing tests can be distinguished by the naked eye in as little as 1 min. Blood disorders, such as thalassemia, can also be distinguished using the device. The required blood volume for the test is just 1 µL, which can be obtained by the less invasive finger pricking method. The low reagent consumption, manual driving force, low-cost of parts, high yield, and robust fabrication process make this device sensitive, accurate, and simple enough to use without specialized training in resource constrained settings.

Blood grouping based on PCR methods and agarose gel electrophoresis.

The study of erythrocyte antigens continues to be an intense field of research, particularly after the development of molecular testing methods. More than 300 specificities have been described by the International Society for Blood Transfusion as belonging to 33 blood group systems. The polymerase chain reaction (PCR) is a central tool for red blood cells (RBC) genotyping. PCR and agarose gel electrophoresis are low cost, easy, and versatile in vitro methods for amplifying defined target DNA (RBC polymorphic region). Multiplex-PCR, AS-PCR (Specific Allele Polymerase Chain Reaction), and RFLP-PCR (Restriction Fragment Length Polymorphism-Polymerase Chain Reaction) techniques are usually to identify RBC polymorphisms. Furthermore, it is an easy methodology to implement. This chapter describes the PCR methodology and agarose gel electrophoresis to identify the polymorphisms of the Kell, Duffy, Kidd, and MNS blood group systems.

Reducing unnecessary preoperative blood orders and costs by implementing an updated institution-specific maximum surgical blood order schedule and a remote electronic blood release system.

BACKGROUND: Using blood utilization data acquired from the anesthesia information management system, an updated institution-specific maximum surgical blood order schedule was introduced. The authors evaluated whether the maximum surgical blood order schedule, along with a remote electronic blood release system, reduced unnecessary preoperative blood orders and costs. METHODS: At a large academic medical center, data for preoperative blood orders were analyzed for 63,916 surgical patients over a 34-month period. The new maximum surgical blood order schedule and the electronic blood release system (Hemosafe; Haemonetics Corp., Braintree, MA) were introduced mid-way through this time period. The authors assessed whether these interventions led to reductions in unnecessary preoperative orders and associated costs. RESULTS: Among patients having surgical procedures deemed not to require a type and screen or crossmatch (n = 33,216), the percent of procedures with preoperative blood orders decreased by 38% (from 40.4% [7,167 of 17,740 patients] to 25.0% [3,869 of 15,476 patients], P < 0.001). Among all hospitalized inpatients, the crossmatch-to-transfusion ratio decreased by 27% (from 2.11 to 1.54; P < 0.001) over the same time period. The proportion of patients who required emergency release uncrossmatched blood increased from 2.2 to 3.1 per 1,000 patients (P = 0.03); however, most of these patients were having emergency surgery. Based on the realized reductions in blood orders, annual costs were reduced by $137,223 ($6.08 per patient) for surgical patients, and by $298,966 ($6.20/patient) for all hospitalized patients. CONCLUSION: Implementing institution-specific, updated maximum surgical blood order schedule-directed preoperative blood ordering guidelines along with an electronic blood release system results in a substantial reduction in unnecessary orders and costs, with a clinically insignificant increase in requirement for emergency release blood transfusions.

Paper-based device for rapid typing of secondary human blood groups.

We report the use of bioactive paper for typing of secondary human blood groups. Our recent work on using bioactive paper for human blood typing has led to the discovery of a new method for identifying haemagglutination of red blood cells. The primary human blood groups, i.e., ABO and RhD groups, have been successfully typed with this method. Clinically, however, many secondary blood groups can also cause fatal blood transfusion accidents, despite the fact that the haemagglutination reactions of secondary blood groups are generally weaker than those of the primary blood groups. We describe the design of a user-friendly sensor for rapid typing of secondary blood groups using bioactive paper. We also present mechanistic insights into interactions between secondary blood group antibodies and red blood cells obtained using confocal microscopy. Haemagglutination patterns under different conditions are revealed for optimization of the assay conditions.

Economic and workflow analysis of a blood bank automated system.

BACKGROUND: This study compared the estimated costs and times required for ABO/Rh(D) typing and unexpected antibody screening using an automated system and manual methods. METHODS: The total cost included direct and labor costs. Labor costs were calculated on the basis of the average operator salaries and unit values (minutes), which was the hands-on time required to test one sample. To estimate unit values, workflows were recorded on video, and the time required for each process was analyzed separately. RESULTS: The unit values of ABO/Rh(D) typing using the manual method were 5.65 and 8.1 min during regular and unsocial working hours, respectively. The unit value was less than 3.5 min when several samples were tested simultaneously. The unit value for unexpected antibody screening was 2.6 min. The unit values using the automated method for ABO/Rh(D) typing, unexpected antibody screening, and both simultaneously were all 1.5 min. The total cost of ABO/Rh(D) typing of only one sample using the automated analyzer was lower than that of testing only one sample using the manual technique but higher than that of testing several samples simultaneously. The total cost of unexpected antibody screening using an automated analyzer was less than that using the manual method. CONCLUSIONS: ABO/Rh(D) typing using an automated analyzer incurs a lower unit value and cost than that using the manual technique when only one sample is tested at a time. Unexpected antibody screening using an automated analyzer always incurs a lower unit value and cost than that using the manual technique.

A study of the transport and immobilisation mechanisms of human red blood cells in a paper-based blood typing device using confocal microscopy.

Recent research on the use of bioactive paper for human blood typing has led to the discovery of a new method for identifying the haemagglutination of red blood cells (RBCs). When a blood sample is introduced onto paper treated with the grouping antibodies, RBCs undergo haemagglutination with the corresponding grouping antibodies, forming agglutinated cell aggregates in the paper. A subsequent washing of the paper with saline buffer could not remove these aggregates from the paper; this phenomenon provides a new method for rapid, visual identification of the antibody-specific haemagglutination reactions and thus the determination of the blood type. This study aims to understand the mechanism of RBC immobilization inside the paper which follows haemagglutination reactions. Confocal microscopy is used to observe the morphology of the free and agglutinated RBCs that are labelled with FITC. Chromatographic elution patterns of both agglutinated and non-agglutinated RBCs are studied to gain insight into the transport behaviour of free RBCs and agglutinated aggregates. This work provides new information about RBC haemagglutination inside the fibre network of paper on a microscopic level, which is important for the future design of paper-based blood typing devices with high sensitivity and assaying speed.

Exponential error reduction in pretransfusion testing with automation.

BACKGROUND: Protecting the safety of blood transfusion is the top priority of transfusion service laboratories. Pretransfusion testing is a critical element of the entire transfusion process to enhance vein-to-vein safety. Human error associated with manual pretransfusion testing is a cause of transfusion-related mortality and morbidity and most human errors can be eliminated by automated systems. However, the uptake of automation in transfusion services has been slow and many transfusion service laboratories around the world still use manual blood group and antibody screen (G&S) methods. STUDY DESIGN AND METHODS: The goal of this study was to compare error potentials of commonly used manual (e.g., tiles and tubes) versus automated (e.g., ID-GelStation and AutoVue Innova) G&S methods. Routine G&S processes in seven transfusion service laboratories (four with manual and three with automated G&S methods) were analyzed using failure modes and effects analysis to evaluate the corresponding error potentials of each method. RESULTS: Manual methods contained a higher number of process steps ranging from 22 to 39, while automated G&S methods only contained six to eight steps. Corresponding to the number of the process steps that required human interactions, the risk priority number (RPN) of the manual methods ranged from 5304 to 10,976. In contrast, the RPN of the automated methods was between 129 and 436 and also demonstrated a 90% to 98% reduction of the defect opportunities in routine G&S testing. CONCLUSION: This study provided quantitative evidence on how automation could transform pretransfusion testing processes by dramatically reducing error potentials and thus would improve the safety of blood transfusion.

Evaluation of two automated instruments for pre-transfusion testing: AutoVue Innova and Techno TwinStation.

BACKGROUND: Despite the advances in total laboratory automation, a considerable amount of work in blood banks is still done using outdated manual methods. Some automated pre-transfusion testing instruments have recently been developed. Of these, we evaluated and compared the AutoVue Innova (Ortho, USA) and the Techno TwinStation (DiaMed AG, Switzerland). METHODS: Forward and reverse ABO/Rh typing and unexpected antibody screening and identification tests were performed on 4,628 samples using the manual method and the two automated instruments. Two different anticoagulants (EDTA and citrate) were compared in ABO/Rh typing and unexpected antibody screening tests. Titrating studies were conducted on the following 7 dilutions using 5 samples of irregular antibodies with anti-E, anti-E & -c, anti-D, and anti-Le(a) with anti-Fy(a): 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, and 1:128. The test throughput per hour, the time required to perform 1 and 100 tests, and a simulation test for total events occurring in 1 day were also measured. RESULTS: No erroneous results were reported between the two instruments and the manual method. Discrepancies observed in 10 cases (0.4%) of ABO/Rh typing were of higher intensity with AutoVue Innova than with the manual method. AutoVue Innova exhibited the highest sensitivity in the titrating study and throughput performance compared with the manual method and the Techno TwinStation. Especially in the throughput and time required to complete 100 antibody screening tests, AutoVue Innova had a 3.3- and 3.5-fold higher performance, respectively, than Techno TwinStation. CONCLUSIONS: Because both of the two fully automated instruments (AutoVue Innova and Techno TwinStation) had high levels of accuracy and performance, it is expected that use of fully automated instruments will reduce human labor, turnaround time, and operator error in the blood bank.

Microfluidics: a technology coming of age.

The number of applications and products utilising microfluidics technology has been growing rapidly. This article highlights the progress of this maturing technology and the significant factors that make it a valuable tool for new product development.

[Automated serial diagnosis of donor blood samples. Ergonomic and economic organization structure]. / Automatisierte Seriendiagnostik von Spenderblutproben. Ergonomische und ökonomische Organisationsstrukturen.

A comprehensive computer-aided administration-system for blood-donors is presented. Ciphered informations of barcode-labels allow the automatic and nevertheless selective pipetting of samples by pipetting-robots. Self-acting analysis-results are transferred to a host-computer in order to actualize a donor data-base.

[Introduction of a new card for the "bedside test"]. / Vorstellung einer neuen Karte für den "Bedside-Test".

A new card for the obligatory ABO-group test is presented. There is sufficient space to perform the test by mixing patient and donor blood to the relevant antisera. As it does not offer any further information, testing for anti-AB has been deleted. Contaminated areas can easily be discarded afterward, minimizing any risk of infection. Only the documentation on the remaining portion of the card is legally important and needs to be entered into the patient's records. Choosing a new manufacturer has resulted in a very low price.

Microtest for red cell typing.

A simple microtest for red cell (RBC) typing was developed which required 0.002 ml of reagents per test. After mixing RBCs with antibody, the microtray was incubated upside down for 10 to 15 minutes at 37 degrees C, and 10 minutes at room temperature. The trays were read after reinversion and allowing 10 to 15 minutes for the RBCs to settle. Antibodies must be selected that react under these conditions. Two examples each of anti-A, -B, -C, -D, -E, -c, -M, and -N were tested against a panel of 500 individuals. The results were generally concordant with each other and with the conventional tube test results. The procedure is simple to perform and involves minimal costs for reagent antisera.

[Automation of immunohematologic testing activities at French blood transfusion centers]. / Automatisation des activités de contrôles immunohématologiques dans les établissements de transfusion sanguine français.

In May 1982, a questionnaire was sent to all of the 170 French Blood Transfusion Services (BTS), on behalf of the French Society of Blood Transfusion. The purpose was to determine the types of automated equipment used for immunohematological controls, the way in which they are used and the result of automation and computerization in daily laboratory operations. We received 135 replies (80%). A generalized conclusion can be drawn from the collected information. 50% of the respondents are neither automated nor computerized. 30% are both automated and computerized. 10% are automated but not computerized and 8% are not automated but are computerized. In the field of automated serology there is an increased tendency to complete the ABO/Rh testing by Cc D Ee and Kell phenotyping. The use of computers allows the current test determination to be compared with previous donation data. However, no fully automated equipment, which can conduct antibody screening, exists, cost effectively, in small or average BTS. In France, there has been a significant increase in automation between 1970 and 1980 but only the most important BTS have carried out automation at the same time as computerization. The smaller BTS have usually become automated without becoming computerized. In 1978, Codabar was first used. This has been one of the principal advances of the last 10 years, allowing all the users of automation to start moving towards complete computerization. This advance was assisted by the use of prepackaged software. This questionnaire also determined that the current emphasis is now to computerize administrative and management activities before laboratory activities. This survey has been conducted during a turning point of the automation of French BTS. It shows that they are, on the whole, satisfied with their automation. As far as the safety and the efficiency of the service are concerned, it is only fair to consider that the main purposes of the automation have been achieved. But in terms of cost, and serological accuracy for antibody screening, a new generation of automated equipment should appear to satisfy the users in the nineties.