In addition, chemical substance chemical preservatives are used sometimes, and these ought to be carefully evaluated concerning if they might impact the researcher’s capability to detect the dairy constituent appealing

In addition, chemical substance chemical preservatives are used sometimes, and these ought to be carefully evaluated concerning if they might impact the researcher’s capability to detect the dairy constituent appealing. The primary reason for this record is to, using evidence gleaned in the literature and expert opinion, delineate a best practices framework related to human milk collection, handling, and storage for COVID-19 research related to breastfeeding. and investigators should openly share their methods in published materials. Otherwise, the risks of inconsistent test results from preanalytical and analytical variation, false positives, and false negatives are unacceptably high and the ability to provide public health guidance poor. In this study, we provide best practices for collecting human milk samples for COVID-19 research with the intention that this will also be a useful guideline for future pandemics. Keywords:human milk, breast milk, COVID-19, methods, collection, pathogen == Background == Human milk is a complex emulsion consisting of a vast array of constituents providing not only nutrition but also protection from pathogens. Concentrations of these constituents vary within an individual, across the lactation period, and even within a feed. Although we do not understand all the factors driving this variability, we know a substantial amount regarding how some factors influence concentrations of some milk constituents. For instance, total lipid content of milk is affected by time postpartum, time of day, time since last feeding, portion of an individual feed (fore- versus hindmilk), maternal body fat level, and in some cases maternal diet.14To complicate matters, lipids and cells can adhere to some types of collection containers that can impact research results,5and some milk constituents (e.g., viral particles and RNA) can be entrapped in the lipid fraction or other compartments such as exosomes.610 Researchers studying human milk composition should, therefore, consider these factors when designing their protocols for collecting human milk to study its composition. For example, collecting a foremilk sample in the morning using an inappropriate collection container may easily lead Rabbit Polyclonal to WEE2 to inaccurate quantification of milk’s Menaquinone-4 lipophilic compounds. Another example is usually host RNA, which, although in relatively high concentrations in milk, is usually quickly degraded by intrinsic RNases3,11; as such, milk must be immediately processed or snap frozen for accurate quantification of host RNA. For other constituents (e.g., iron and lactose), concentrations in milk are Menaquinone-4 less prone to variation12,13; in these situations, sample collection and storage protocols can be less stringent. Milk composition may even vary between breastsespecially regarding immune factors; this fact has been particularly important in the study of HIV transmission through breastfeeding.14For other milk components, such as microbiota, there exists very little research characterizing modifiable factors (e.g., time of day and time within feed) related to variation; in these situations, best practices and standardization (although not optimization) are typically employed to ensure that samples are collected in a way that reduces risk of contamination and allows data to be compared across studies. In summary, because human milk composition is highly variable within and among women and can be influenced by many biological and methodological factors, it is fundamentally important that researchers consider and report core aspects of milk collection, handling, and storage when studying it. These aspects include expression mode (electric pump or manual expression), time of day, time postpartum, complete versus partial expression (and if the latter, whether foremilk or hindmilk was collected), breast preparation (was the breast cleaned and if so Menaquinone-4 with what), collection container material (and whether it was sterile), and storage conditions (e.g., time until refrigeration or freezing, temperature, and duration of storage). In addition, sometimes chemical preservatives are utilized, and these should be carefully evaluated as to whether they might impact the researcher’s ability to detect the milk constituent of interest. The primary purpose of this document is usually to, using evidence gleaned from the literature and expert opinion, delineate a best practices framework related to human milk collection, handling, and storage for COVID-19 research related to breastfeeding. Although we recognize that each microbe is unique, it is our hope that this framework will also be applicable to other pathogenic RNA viruses, DNA viruses, bacteria, and maybe even other organismal taxa. In addition to including information related to the study of presence/absence and viability of these types of pathogens, we provide information on how one might best collect milk for the study of immunoglobulins, cytokines, and other soluble factors, and immune cells.