Specimen blindness

Among the Salamandridae, displaced Western newts, Taricha rivularis, home to the same section of a stream year after year. Blinded newts still homed successfully, and anosmic specimens were reduced in their homing ability but still did not move in random fashion. They return to their home pond from up to 12km(Twitty, 1966). Another salamander, tested in the... 

ASTM D 6400-04 (homopolymers) >60% of theoretical CO2 evolution after 180 days ASTM D 6400-04 (heteropolymers) >90% of theoretical CO2 evolution after 180 days <10% of the weight of the specimen shall fail to pass through a >2-mm fraction sieve Density, dry solids, volatile solids, salt content, pH, content of elemental N, P, Mg, Ca Rate of germination and biomass >90% of blind value of compost without polymer... 

The next step in validation was to test known positive specimens that had been archived. This approach was important in validating a variety of disorders. In today s environment, however, these specimens, critical to method validation, have become increasingly more difficult to obtain due to privacy concerns and regulations. For example, it was important to obtain blood spots analyzed previously by other methods and compare results in a blinded fashion in order to validate the newer methodology. A fundamental paper for demonstrating the improvement of PKU detection was carried out using this approach. 

A blind test was conducted with a cotton sample 814 days old. A single creep test was performed and the age was estimated. The result achieved was an estimated age of 214 days. This result seems to indicate a rather large error. However, when the datum is plotted, the point is not very far from the curve. In fact, it is quite consistent with the trend set by the data for 47- and 400-year-old samples and suggests that the curve rather than the 814-day datum is incorrect. In view of the limited number of calibration points used to fit the curves, this explanation seems plausible. Consequently, the curve in Figure 8 represents a curve fitted to all cotton specimens measured, including the 814-day specimen. The fitted equations presented here should be used only to evaluate the... 

A series of studies in Sydney is underway, attempting to identify markers of early disease using both visual inspection and the SCS method. Visual inspection of the MRS data indicated in 11% of cases that the routine histopathology was incorrect, due to incomplete examination of the tissue specimen. As a consequence, the pathology of these and another 15% of cases were reviewed blind. The tissues examined by MRS were serially sectioned, and sections every 100 pm were examined. The inaccuracy of routine hospital pathology procedures, where 5 pm sections at only two or three levels are examined, was highlighted. 

Some estimates of the precision of various typical modem procedures are given in Table 3. General clinical chemists may well be surprised at some of the values when compared with objective experience in other areas. Thus it is well known that the estimation of serum bilimbin has a coefficient of variation (C.V.) of around 15% in most laboratories, and that with creatinine a value of 8-10% is fairly normal (W3). In a recent blind (but not double-blind) interlaboratory trial of a standardized method for 17-ketogenic steroids and one for 17-ketosteroids, Gray et al. (GIO) obtained C.V. s varying between 4% and 14% for both methods. Six of the ten laboratories cooperating in the trial had special steroid experience and were asked to obtain duplicate estimates of any thirty routine specimens of urine. These results are for two well-established and relatively simple procedures. 

In order to obtain representative and reproducible values, it is important to take into account some methodological procedures. All sections obtained from the different experimental and control groups must be processed in parallel at the same time, under the same experimental conditions. Theoretically, the measurement of the density of a single specimen should always be the same value. Unfortunately, density values are only replicable under well-controlled conditions of measuranent. All measurements should be performed by at least two independent observers in blind conditions. 

Throat swabs, blood withdrawals, nasal washes and saliva samples are isolated on the indicated (X) days. Blood specimens (3 mL) are taken by venipuncture from the cephalic vein. Nasal washes are collected by instilling 1.5 mL of sterile phosphate-buffered saline (PBS) into the nostril and immediately aspirating wash fluid and secretions with a sterile S5uinge. Saliva specimens are collected by aspiration from the cheek pouch. Prior to throat swabbing, clinical scoring of tonsillitis and pharyngeal erythema severity is performed by a trained veterinarian who is blinded to the two animal groups. 

What are the requirements for submitting blind specimens to a laboratory ... 

What happens if the laboratory reports a result different from that expected for a blind specimen ... 

An employer or consortium/third party administrator (C/TPA) with an aggregate of 2,000 or more DOT-covered employees must send blind specimens to the laboratories it uses. 

An employer or C/TPA with an aggregate of fewer than 2,000 DOT-covered employees is not required to provide blind specimens. 

To each laboratory to which at least 100 specimens are sent in a year, the employer or C/TPA must send the equivalent of one percent of the specimens sent to the laboratory, up to a maximum of 50 blind specimens per quarter. The submissions must be spread evenly throughout the year. 

All negative, positive, adulterated, and substituted blind specimens submitted must be certified by the suppher and must have supplier-provided expiration dates. 

Drug positive blind specimens must be certified by immunoassay and GC/MS to contain a drug(s)/metabohte(s) between 1.5 and 2 times the initial drug test cutoff concentration. 

Adulterated blind specimens must be certified to be adulterated with a specific adulterant using appropriate confirmatory validity test(s). 

Substituted blind specimens must be certified for creatinine concentration and specific gravity to satisfy the criteria for a substituted specimen using confirmatory creatinine and specific gravity tests. 

The employer or C/TPA must ensure that each blind specimen is indistinguishable to the laboratory from a normal specimen ... 

The blind specimens must be submitted to the laboratory using the same channels as all employees specimens ... 

All blind specimens must include split specimens. 

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