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Shigella is the most common foodborne pathogen and can cause bacillary dysentery. Therefore, it is necessary to detect Shigella rapidly and accurately, but it is difficult for traditional methods to meet these requirements. In this study, monoclonal antibodies (mAbs) were prepared using a recombinant invasive plasmid antigen C (IpaC) protein, which is specifically located on the outer membrane of Shigella. Based on our mAbs 2G11 and 5A11, a colloidal gold lateral flow immunochromatographic (LFIA) test strip method for the detection of several serotypes of Shigella was produced. The sensitivity of the LFIA strip was 1 × 105 CFU mL−1 for four groups, and seven serotypes of Shigella. The applicability of the strip was tested using spiked milk and meat samples and the results showed that Shigella could be detected in these matrices.

BACKGROUND: Salivary urea concentrations correlate with serum urea concentrations in dogs and humans. Salivary urea concentrations can now be determined semi-quantitatively using a salivary urea test strip method that has been validated for use in humans. OBJECTIVES: We aimed to evaluate the repeatability of the salivary urea test strip score, and the correlation between the salivary urea test strip scores and serum urea concentrations in dogs. METHODS: Intra-run and inter-run variabilities were determined (n = 10 in triplicate). Correlations between salivary urea test strip scores and serum urea concentrations in dogs were assessed using the Spearman's correlation coefficient. Receiver operator curve analysis was used to evaluate the diagnostic performance of the salivary urea test strip score to identify dogs with serum urea concentration >7.4 mmol/L (upper limit of laboratory RI). RESULTS: The intra-run repeatability was good (28/30 concordant results) whereas the inter-run repeatability was moderate (23/30 concordant results). Salivary and serum urea concentrations showed a moderately positive correlation (rs = .63, n = 33; P < .0001). A salivary urea test strip score ≥4 was 57% sensitive and 96% specific for detecting a serum urea concentration >7.4 mmol/L. CONCLUSIONS: Uremia can be detected using salivary urea test strips in dogs. Based on our preliminary data, salivary urea test strip scores of 1 or 2 might exclude clinically relevant uremia in most cases; however, it is recommended that the salivary urea test be repeated in dogs with a test strip score of 3. Dogs with a salivary urea test strip score of ≥4 would likely require additional investigations.

This study was designed to prepare and evaluate the sensitivity and specificity of a Norovirus GI and GII fluorescent particles combined detection test strip method. Using selected chromatographic materials and antibodies specific to Norovirus GI and GII, the Norovirus GI and GII fluorescent particles combined detection test strip (tested method) was prepared as a conventional double antibody sandwich. The samples assayed included cultured rotavirus and 465 specimens from patients with symptoms of gastrointestinal infection. Norovirus was detected using the tested method and a reference method (CerTest Norovirus GI-GII test card). The results indicated that the sensitivity of the tested method was 4 (for GI detection) or 8 times (for GII detection) greater than the reference method. Neither of the two methods cross-reacted with rotavirus and so on. For specimens, 29 were found to be negative by the reference method and positive by the tested method, and 8 were found to be negative by the tested method and positive by the reference method. Furthermore, a retesting of these samples by qPCR showed that 28 of the 29 were positive, and 3 of the 8 were positive. In summary, the Norovirus GI and GII fluorescent particles combined detection test strip was successfully prepared and had good detection performance.

Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one. Hardness of water also can be tested by a more rapid test strip method. The commercial test strips contain EDTA and an indicator chemical to cause a color change when the calcium and magnesium in water react with the EDTA. In this laboratory exercise, hardness of water is determined by both the EDTA titration method and with Quantab® test strips.

Fetal blood lactate can easily and safely be measured with the new microvolume lactate meter. The system requires only 5µl of blood and gives the result in 60 seconds. As opposed to pH meters, the lactometer is considerably cheaper and does not require trained staff or regular attention from a technician. Trials have shown the levels of lactate and pH in fetal scalp blood to be comparable in predicting low Apgar scores at delivery as well as the need for neonatal intensive care unit admission. Lactate concentration in umbilical artery blood has also been shown to have the same predictive properties as pH in relation to perinatal morbidity and mortality. Owing to its simplicity of performance, lactate analysis with the new test strip method is an attractive complement of intrapartum fetal monitoring.

A new test strip method was used to determine the lactate concentration in fetal scalp blood during normal labor. Sixty-six fetal scalp blood samples were collected at cervical dilatations between 4 cm and 10 cm. The mean lactate value was 1.7 +/- 0.8 mmol/l simultaneously (IS.D.) and the mean pH sampled simultaneously was 7.36 +/- 0.04 (IS.D.). The corresponding values for base deficit was 2.1 (+/- 1.9) and for pCO2 5.8 (+/- 0.8). No difference was seen in lactate concentrations or pH values in early compared to late first stage of labor. The mean lactate concentration in the umbilical artery immediately after delivery was 3.7 mmol/l +/- 1.2 (IS.D.). The method was easy to handle and gave the result within 60 seconds.

The cause of a respiratory deterioration in a critically ill patient frequently remains unknown. Pulmonary aspiration of enteral feed during tracheal intubation may be recognised at the bedside by the appearance of feed in the tracheal aspirate but is commonly unrecognised. To reduce aspiration it is important to be able to detect it at the bedside and hence alter management to reduce risk factors. Techniques to detect feed aspiration using food colouring have poor sensitivity and are linked with mortality in septic patients [1]. The standard glucose oxidase strip method for detecting aspiration is also insensitive because the glucose levels in feeds are similar to those of normal tracheal aspirates. We have previously described a modified glucose oxidase test strip method with an improved sensitivity [2] whereby the glucose concentration of the feed is markedly increased.

To investigate the feasibility of using salivary urea nitrogen as an index of renal glomerular filtration rate, we developed and applied a new analytical system consisting of a urease-containing test strip and an automatic reflectance spectrometer. The concentrations of urea nitrogen so determined correlate well (r = 0.93) with concentrations in serum. These preliminary data suggest that our method can be used routinely as a simple and reliable means of detecting abnormalities of renal function.

We have developed a dry reagent strip system for measuring lactate in whole blood. The test strip contains lactate oxidase (no EC number assigned), horseradish peroxidase (EC 1.11.1.7), and N-ethyl-N-(2-hydroxy-3-sulfopropyl)-m-toluidine. The system is designed to measure with a reflectometer the color that developed in the test strip, although the lactate concentration can be estimated without the reflectometer. The between-run coefficients of variation for controls at three concentrations were 2.9-5.3%. The lactate concentrations in blood samples from healthy subjects before and after exercise correlated well (r = 0.97) with the results measured by the comparison method with the use of lactate oxidase. This dry reagent strip system provides a convenient and rapid test for measuring blood lactate in clinical and sports medicine.

A novel and rapid method (Strep Strip, Lab M) for identification of Streptococcus pyogenes was evaluated. The method combines the established test for pyroglutamyl aminopeptidase (PYR) with a rapid chromogenic test for beta-glucosidase on a paper strip. The test was evaluated with 274 clinical isolates and 237 culture collection isolates of beta-haemolytic streptococci. Streptococcus pyogenes was identified with 100% specificity. Six isolates identified as Lancefield group A and which might therefore be assumed to be Streptococcus pyogenes were shown by the test strip method not to be this species. The beta-glucosidase test on the test strip allowed differentiation between enterococci and Streptococcus pyogenes (both PYR positive) in all cases. The test strip method represents an economical and accurate method for identification of Streptococcus pyogenes in clinical material.

During a 4-year routine screening programme for cystic fibrosis (CF) 15 464 specimens were examined for raised meconium albumin levels by a test strip method and by electroimmunoassay. The incidence of false-positive results was about 5 per 1000 specimens in either test. This could be reduced by 90% by determining the ratio of albumin : alpha-1-trypsin inhibitor (a ratio below 2.0 being considered as a negative result), and it could be reduced to zero by determining the ratio in subsequent faecal specimens. Three of 12 meconium specimens from infants with proved CF gave false-negative results in all 3 tests. The other 9 specimens had greater than 100 mg albumin/g dry weight and albumin: alpha-1-trypsin inhibitor ratios of greater than 3.0; in subsequent faecal specimens the ratios were over 4.0. 176 meconium specimens from elsewhere in the UK were examined and these included 23 from infants who were subsequently proved to have CF. Six of these 23 CF specimens gave false-negative results, the other 17 being strongly positive. The origins of meconium serum protein suggest that infants with CF in whom meconium gives false-negative results have normal pancreatic functions at birth. The specificity of current meconium tests therefore cannot be improved as they depend on pancreatic dysfunction.

NUMEROUS titrametric, manometric, colorimetric, and electrometric methods of determining the activity of cholinesterase (ChE) have been reported.1Among these quantitative measurements, the electrometric method of Michel2and the colorimetric method of de la Huerga et al3are the most widely used. Simpler methods based upon the change of color of suitable indicators have been reported.4,5However, all of these require facilities which are not usually available in the average clinical laboratory. Limperos and Ranta6described a semiquantitative method of determining ChE in the whole blood by observing the color change of bromothymol blue. This was modified and adapted for use as a screening test.7, 8Herzfeld and Stumpf9reported on a test-paper method, the results of which were recently demonstrated by other investigators to be in reasonably good agreement with results obtained by the manometric and the electrometric methods.10, 11This ChE

OBJECTIVE To compare the measurement of lactate in fetal scalp and umbilical artery blood by a new dry reagent strip method with a commercially available enzymatic method using plasma (Monotest). DESIGN Comparative study. SUBJECTS Fetal scalp blood samples were obtained during labour from 24 fetuses and umbilical artery blood samples were obtained at birth in a further 51 deliveries. RESULTS The concentration of lactate in scalp and umbilical artery blood measured by the reagent strip method correlated well (r = 0.94, P less than 0.001 and 0.95, P less than 0.001 respectively) with the enzymatic plasma method. The paper strip method tended to give lower readings than the enzymatic method when the fetal haematocrit was greater than or equal to 50%. CONCLUSIONS The new dry reagent strip method which takes only 1 min to carry out and requires only 20 microliters of blood seems to be handy and reliable. This system provides a convenient and rapid test for measuring fetal blood lactate.

• As an important aspect of newborn care, the rapid assessment of glucose homeostasis is often accomplished by a glucose oxidase—peroxidase chromagen test strip method, either alone or with a reflectance colorimeter. The precision of these techniques has been established, but few studies have determined accuracy in an intensive care setting. We performed the following study. During the time of routine heelstick blood sampling, the nurses collected 90 complete study sets for glucose analysis from 43 neonates. Dextrostix, Ames Meter, Chemstrip bG, and Stat Tek Meter determinations were performed according to manufacturers' instructions. Concurrent determination of blood glucose level by a glucose analyzer (Beckman) served as a standard for comparison. There was no significant difference in estimation of true blood glucose concentration among the rapid methods tested. The marked variability of results suggests only modest accuracy in estimating whole blood glucose concentration when employed in the routine neonatal clinical setting. These data indicate that the results from rapid blood glucose estimation techniques require confirmation by conventional laboratory methods prior to therapeutic intervention. ( Am J Dis Child 1982;136:1051-1053)