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BMJ (Clinical Research Ed.) Dec 2006Unregulated expansion requires evidence of benefit
Unregulated expansion requires evidence of benefit
Topics: Breast Feeding; Milk Banks; Milk, Human; Preservation, Biological; Tissue Donors
PubMed: 17138973
DOI: 10.1136/bmj.39034.651563.80 -
Journal of Structural Biology Jul 2017We present here a new CryoEM grid boxes storage system designed to simplify sample labeling, tracking and retrieval. The system is based on the crystal pucks widely used...
We present here a new CryoEM grid boxes storage system designed to simplify sample labeling, tracking and retrieval. The system is based on the crystal pucks widely used by the X-ray crystallographic community for storage and shipping of crystals. This system is suitable for any cryoEM laboratory, but especially for large facilities that will need accurate tracking of large numbers of samples coming from different sources.
Topics: Automation, Laboratory; Cryoelectron Microscopy; Preservation, Biological; Research Design; Specimen Handling
PubMed: 28433496
DOI: 10.1016/j.jsb.2017.04.005 -
Microbial Biotechnology Sep 2019The preservation of the viability of microorganisms in probiotic formulations is the most important parameter ensuring the adequate concentration of live microorganisms...
The preservation of the viability of microorganisms in probiotic formulations is the most important parameter ensuring the adequate concentration of live microorganisms at the time of administration. The formulation and processing techniques used to produce these probiotic formulations can influence the preservation of the microbial viability. However, it is also required that the bacteria maintain their key probiotic capacities during processing, formulation and shelf life. In this study, we investigated the impact of spray-drying on different cell wall properties of the model probiotic strain Lactobacillus rhamnosus GG, including its adherence to intestinal epithelial cells. The dltD gene knock-out mutant, L. rhamnosus GG CMPG5540, displaying modified cell wall lipoteichoic acids, showed significantly increased colony-forming units after spray-drying and subsequent storage under standard conditions compared to wild-type L. rhamnosus GG. In contrast, disruption of the biosynthesis of exopolysaccharides or pili expression did not impact survival. However, spray-drying did significantly affect the adherence capacity of L. rhamnosus GG. Scanning electron microscopy confirmed that the pili, key surface factors for adherence to intestinal cells and mucus, were sheared off during the spray-drying process. These data thus highlight that both the functionality and viability of probiotics should be assessed during the spray-drying process and subsequent storage.
Topics: Bacterial Adhesion; Colony Count, Microbial; Dehydration; Desiccation; Epithelial Cells; Lacticaseibacillus rhamnosus; Microbial Viability; Preservation, Biological; Probiotics
PubMed: 31225698
DOI: 10.1111/1751-7915.13426 -
Rapid Communications in Mass... Jan 2020Stable isotope analysis is used to investigate the trophic ecology of organisms and, in order to use samples from archived collections, it is important to know whether... (Comparative Study)
Comparative Study
RATIONALE
Stable isotope analysis is used to investigate the trophic ecology of organisms and, in order to use samples from archived collections, it is important to know whether preservation methods alter the results. This study investigates the long-term effects of four preservation methods on isotopic compositions and isotopic niche parameters of sea stars.
METHODS
We assessed the effects of preservation method (freezing, drying, formaldehyde, ethanol) and duration (0, 1, 3, 6, 9, 12, 24 months) on the stable isotope ratios of carbon, nitrogen and sulfur of sea star tissues. Isotopic ratios were measured using continuous-flow elemental analysis and isotope ratio mass spectrometry. We also monitored the evolution of commonly used ecological metrics (isotopic niche parameters) throughout the experiment.
RESULTS
Clear changes in δ C values were observed for samples stored in formaldehyde and ethanol. None of the preservation methods had significant or consistent effects on δ N values. Formaldehyde preservation induced a decrease in δ S values. All these changes could be mitigated using correction factors. Isotopic niche parameters slightly changed over time when computed with δ C and δ N values, but inconsistent variations occurred when computed with δ C and δ S values.
CONCLUSIONS
Overall, these results show that preservation may affect the stable isotope ratios of sea stars. Correction factors can be used to mitigate the effects of the preservation method on stable isotope ratios. Isotopic niche parameters are overall unchanged. Consequently, in most cases, museum samples are suitable for calculation of isotopic niche parameters.
Topics: Animals; Carbon Isotopes; Mass Spectrometry; Nitrogen Isotopes; Preservation, Biological; Starfish
PubMed: 31509618
DOI: 10.1002/rcm.8589 -
The Journal of Reproduction and... Oct 2011Freeze-drying (lyophilization) has been proposed as an alternative method for sperm preservation to overcome the disadvantages of the current cryopreservation method... (Review)
Review
Freeze-drying (lyophilization) has been proposed as an alternative method for sperm preservation to overcome the disadvantages of the current cryopreservation method such as the high maintenance cost of frozen stocks, the problems associated with transportation of frozen materials and the potential risk of total loss of the frozen stock. Since freeze-dried spermatozoa after rehydration lose their motility, which is an essential requirement to complete physiological fertilization, a relatively difficult microinsemination technique must be applied to rehydrated spermatozoa. Theoretically, it has been supposed that freeze-dried spermatozoa could maintain their functions and abilities to interact with the oocyte cytoplasm after prolonged storage at refrigerator temperature. However, sufficient yield of transferable blastocysts and production of live offspring derived from freeze-dried sperm samples are still subjects to be challenged and overcome in large domestic species.
Topics: Animals; Cryopreservation; Freeze Drying; Humans; Male; Models, Biological; Reproductive Techniques, Assisted; Semen Preservation; Sperm Injections, Intracytoplasmic; Spermatozoa
PubMed: 22052044
DOI: 10.1262/jrd.11-061o -
PloS One 2022Sequencing-based protocols for studying the human microbiome have unearthed a wealth of information about the relationship between the microbiome and human health. But...
Sequencing-based protocols for studying the human microbiome have unearthed a wealth of information about the relationship between the microbiome and human health. But these microbes cannot be leveraged as therapeutic targets without culture-based studies to phenotype species of interest and to establish culture collections for use in animal models. Traditional sample collection protocols are focused on preserving nucleic acids and metabolites and are largely inappropriate for preserving sensitive anaerobic bacteria for later culture recovery. Here we introduce a novel microbiome preservation kit (BIOME-Preserve) that facilitates recovery of anaerobic bacteria from human stool. Using a combination of culture recovery and shallow whole-genome shotgun sequencing, we characterized the anaerobes cultured from fresh human stool and from human stool held at room temperature in BIOME-Preserve for up to 120 hours. We recovered several species of interest to microbiome researchers, including Bifidobacterium spp., Bacteroides spp., Blautia spp., Eubacterium halii (now Anaerobutyricum hallii), Akkermansia muciniphila, and Faecalibacterium prausnitzii. We also demonstrated that freezing at -80°C did not adversely affect our ability to culture organisms from BIOME-Preserve, suggesting that it is appropriate both as a transport medium and as a medium for longer-term ultra-cold storage. Together, our results suggest BIOME-Preserve is practical for the collection, transport, and culture of anaerobic bacteria from human samples and can help enable researchers to better understand the link between the microbiome and human health and how to leverage that link through novel microbiome-based therapeutics.
Topics: Anaerobiosis; Bacteria; Feces; Female; Humans; Male; Microbiota; Preservation, Biological; Specimen Handling
PubMed: 35061732
DOI: 10.1371/journal.pone.0261820 -
Current Protocols in Molecular Biology Jan 2019In this article, we provide information about culture media, including minimal liquid media, rich liquid media, solid media, top agar, and stab agar. We also provide...
In this article, we provide information about culture media, including minimal liquid media, rich liquid media, solid media, top agar, and stab agar. We also provide descriptions and useful information about tools used with growth media such as inoculating loops, sterile toothpicks, and spreaders. © 2018 by John Wiley & Sons, Inc.
Topics: Agar; Bacteriological Techniques; Colony Count, Microbial; Culture Media; Escherichia coli; Preservation, Biological
PubMed: 30412361
DOI: 10.1002/cpmb.83 -
Parasites & Vectors Jan 2015Near-infrared spectroscopy (NIRS) has been successfully used on fresh and RNAlater-preserved members of the Anopheles gambiae complex to identify sibling species and...
BACKGROUND
Near-infrared spectroscopy (NIRS) has been successfully used on fresh and RNAlater-preserved members of the Anopheles gambiae complex to identify sibling species and age. No preservation methods other than using RNAlater have been tested to preserve mosquitoes for species identification using NIRS. However, RNAlater is not the most practical preservative for field settings because it is expensive, requires basic laboratory conditions for storage and is not widely available in sub-Saharan Africa. The aim of this study was to test several cheaper and more field-friendly preservation methods for identifying sibling species of the An. gambiae complex using NIRS.
METHODS
In this study we describe the use of NIRS to identify sibling species of preserved An. gambiae s. s. and An. arabiensis. Mosquitoes of each species were placed in sample tubes and preserved using one of the following preservation methods: (i) refrigeration at 4°C, (ii) freezing at -20°C, (iii) drying over a silica-gel desiccant, (iv) submersion in RNAlater at room temperature, (v) submersion in RNAlater at 4°C, and (vi) submersion in RNAlater at -20°C. Mosquitoes were preserved for 1, 4, 10, 32 or 50 weeks before they were scanned.
RESULTS
Storage at 4°C was the only preservation method that, up to 32 weeks, did not result in significantly lower predicted values than those obtained from fresh insects. After 50 weeks, however, refrigerated samples did not give meaningful results. When storing for 50 weeks, desiccating samples over silica gel was the best preservation method, with a partial least squares regression cross-validation of >80%. Predictive data values were analyzed using a generalized linear model.
CONCLUSION
NIRS can be used to identify species of desiccated Anopheles gambiae s.s. and Anopheles arabiensis for up to 50 weeks of storage with more than 80% accuracy.
Topics: Animals; Anopheles; Desiccation; Insect Vectors; Preservation, Biological; Silica Gel; Spectroscopy, Near-Infrared
PubMed: 25623484
DOI: 10.1186/s13071-015-0661-4 -
Scientific Reports Oct 2020Ancient DNA (aDNA) analyses necessitate the destructive sampling of archaeological material. Currently, the cochlea, part of the osseous inner ear located inside the...
Ancient DNA (aDNA) analyses necessitate the destructive sampling of archaeological material. Currently, the cochlea, part of the osseous inner ear located inside the petrous pyramid, is the most sought after skeletal element for molecular analyses of ancient humans as it has been shown to yield high amounts of endogenous DNA. However, destructive sampling of the petrous pyramid may not always be possible, particularly in cases where preservation of skeletal morphology is of top priority. To investigate alternatives, we present a survey of human aDNA preservation for each of ten skeletal elements in a skeletal collection from Medieval Germany. Through comparison of human DNA content and quality we confirm best performance of the petrous pyramid and identify seven additional sampling locations across four skeletal elements that yield adequate aDNA for most applications in human palaeogenetics. Our study provides a better perspective on DNA preservation across the human skeleton and takes a further step toward the more responsible use of ancient materials in human aDNA studies.
Topics: Archaeology; Bone and Bones; DNA, Ancient; Ear, Inner; Germany; History, Medieval; Humans; Petrous Bone; Preservation, Biological; Tooth
PubMed: 33106554
DOI: 10.1038/s41598-020-75163-w -
Microbiological Research Jun 2020Freeze-drying technology has been widely considered for decades as a suitable technique to preserve microorganisms. However, protective agents must be added prior to...
Freeze-drying technology has been widely considered for decades as a suitable technique to preserve microorganisms. However, protective agents must be added prior to freeze drying to improve the survival and storage stability of the bacteria. The objective of our study was to evaluate the effect of a new protectant medium containing sucrose (10 %), trehalose (10 %), skimmed milk (10 %) and antioxidants on the viability of gut bacteria under different storage conditions. Two strains were tested, Escherichia coli and Akkermansia muciniphila, as examples of facultative aerobic and anaerobic bacteria, respectively. We studied the cell viability and bacterial morphology in 5 fecal samples in the presence and absence of this protectant medium using plating technique, flow cytometry and scanning electron microscopy. The results of bacterial viability assessed by plating method showed that the protectant medium yielded higher survival rates for both strains whatever the storage conditions (85-93 %) compared to normal saline solution (0.36-37.50 %). It also showed its effectiveness on fecal samples, where bacterial viability after freeze-drying was 89.47 ± 7.63 % and 84.01 ± 7.44 %, as evidenced by flow cytometry analysis and plating method. However unprotected samples showed the lowest cell viability at 19.01 ± 12.88 % and 13.23 ± 9.56 %, as measured by flow cytometry and plating method. In addition, bacterial size and shape were conserved in the protectant medium. In contrast, storage without protectant medium severely damaged bacterial morphology. In conclusion, our study is the first to use morphological features as well as culture-dependant and culture-independent tests to evaluate the effectiveness of a new protectant medium.
Topics: Animals; Bacteria; Culture Media; Freeze Drying; Microbial Viability; Milk; Preservation, Biological; Sucrose; Trehalose
PubMed: 32200250
DOI: 10.1016/j.micres.2020.126454