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HLA-DR Typing by Polymerase Chain Reaction Amplification with Sequence-Specific Primers (PCR-SSP)
Published in M. Kam, Jeffrey L. Bidwell, Handbook of HLA TYPING TECHNIQUES, 2020
Place all the components of the PCR reaction in the bottom of the PCR tube. Change pipette tip for the addition of each component. No mixing of the reaction mixture is required. When using a GeneAmp PCR system 9600 thermal cycler (Perkin-Elmer Cetus Corporation), the overlay with mineral oil is not necessary.
Laboratory Techniques
Published in Niel T. Constantine, Johnny D. Callahan, Douglas M. Watts, Retroviral Testing, 2020
Niel T. Constantine, Johnny D. Callahan, Douglas M. Watts
The pipette is the instrument used for volumetric measurements in all clinical diagnostic laboratories. Obviously, the manner in which the pipette is handled and maintained directly affects the accuracy of laboratory results. The three most common types of pipettes routinely used for HIV testing are transfer (or Pasteur pipettes), serological, and manual (or mechanical).
Animal Models for Phototoxicity Testing
Published in Francis N. Marzulli, Howard I. Maibach, Dermatotoxicology Methods: The Laboratory Worker’s Vade Mecum, 2019
Lark A. Lambert, Wayne G. Warner, Andrija Kornhauser
A micropipet was used to apply the test chemicals, either 10 μl to a 14-mm-diameter area (Lovell and Sanders, 1992) or 25 μl/cm2 to a 15 × 15 mm area (Nilsson et al., 1993). For viscous substances a positive-displacement pipettor should be considered. Nilsson et al. (1993) used four application sites for each guinea pig, and Lovell and Sanders (1992) used six sites per animal. Although several different chemicals might be tested in the same animal, the application sites should preferably be used for testing several concentrations of a single compound. The mixing of different substances may result in unwanted interactions. One disadvantage of using multiple test sites on the same animal is the possibility of uneven radiation doses to each site. Nilsson et al. (1993), however, reported that their test results were not significantly affected by the multiple-site procedure.
Tear Film miRNAs and Their Association With Human Dry Eye Disease
Published in Current Eye Research, 2022
Andrew D. Pucker, William Ngo, Cameron K. Postnikoff, Henry Fortinberry, Jason J. Nichols
Samples then underwent EV isolation.37 Specifically, polyethylene glycol (PEG) 8000 (Fisher; product number: BP233-1) was added to each sample to achieve a final concentration of 10% PEG 8000 in PBS.37 Samples were then stored on ice for one hour and then overnight at 4 °C to promote EV precipitation. Samples were then again put on ice for one hour the next morning to further promote EV precipitation. Samples were centrifuged at 20 000 × g at 4 °C for 20 min in an Eppendorf 5417 R centrifuge. After centrifugation, 100 µL of supernatant from each sample was collected and stored on ice. A portion of the supernatant was collected to determine if any sequenceable RNA was present within the supernatant. The remaining supernatant for each sample was aspirated with a pipette and the pellets were washed once with 100 µL of ice cold 10% PEG 8000 in PBS to remove any potentially remaining supernatant. The wash was aspirated via pipette and discarded. Overall, each initial pooled sample yielded two samples (supernatant and pellet), which directly underwent RNA extraction or morphological characterization.
Fecal calprotectin as a biomarker of intestinal inflammation in ICU patients with diarrhea – testing the pipette method against the collection pin and weighing methods
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2022
Karoline Hardis, Sarah B. Johansen, Janne Eriksen, Kjeld Damgaard, Peter Derek Christian Leutscher, Soren Jepsen
The validation of the pipette method showed higher CV with values of 13% for low concentration and 39% for high concentration in comparison with 8% and 14%, respectively, for the weighing method. Hence, the pipette method did not differ remarkably from the weighing method, especially in the low concentrations. The collection pin has previously been validated using normal consistency stool samples by our department of clinical biochemistry, where the precision was found to be 17% and 26% for fecal calprotectin levels of 73 mg/kg and 178 mg/kg, respectively. Thus, the pipette method demonstrates an acceptable precision when compared to the weighing method. The precision of the pipette method on liquid samples is also similar to that obtained on samples of fecal samples of normal consistency by the collection pin.
Impacts of ingested MWCNT-Embedded nanocomposites in Japanese medaka (Oryzias latipes)
Published in Nanotoxicology, 2021
Melissa Chernick, Alan Kennedy, Treye Thomas, Keana C. K. Scott, Christine Ogilvie Hendren, Mark R. Wiesner, David E. Hinton
Six fish (3 females, 3 males) in each group were processed for histology. Immediately following euthanasia, a disposable extended length fine tip pipette was inserted into the buccal cavity and 10% neutral buffered formalin (10% NBF; VWR) was flushed into a branchial cavity, pharynx, and foregut. Next, microdissection scissors (Ted Pella, Redding, CA) were used to make a ventral incision from the anus to near the pectoral girdle. In order to facilitate the fixation of deep tissues, the pipette was used to gently flush the fixative into the abdominal cavity, making sure to not displace internal organs. Next, specimens were immersed in 10 times volume of 10% NBF and fixed overnight on an orbital shaker at room temperature. Then, one male per treatment group was prepared for transverse sectioning by cutting two crosswise portions. The first portion consisted of the head to just past the operculum, with the second ending just caudally to the abdomen. Cut portions were returned to fixative. All fixed specimens were stored at 4 °C until processing.