Cultivating social relationships and disrupting social isolation in low-income, high-disparity neighbourhoods in Ohio, USA.

Social isolation undermines health. Inequities in social networks exist due to historical and contemporary practices of socioeconomic and racial segregation. Thus, lower income and minority families are less likely to have the number, strength, and variety of social connections as higher income and white families. Therefore, social isolation may contribute to inequities in health and well-being across socioeconomic and racial groups. Disrupting social isolation by strengthening social networks may be a meaningful way to equitably improve population health. In this study we aimed to better understand the factors that influence the formation and sustainment of social connections in neighbourhoods experiencing a disproportionate burden of social needs and poor health outcomes. Participants were recruited through our community-academic partnership, Healthy Homes (HH). Healthy Homes serves families with pregnant women and/or children <6 years in two low-income, high-morbidity neighbourhoods, focusing on supporting families' needs and hopes. Between October 2016 and April 2017, we conducted in-depth qualitative interviews (n = 20) with English-speaking mothers and grandmothers of children under <6 years. Interviews were audio-recorded, transcribed verbatim and independently coded. After applying an a priori code list, we conducted emergent coding to identify additional themes. Themes focused on the social environment, including social connections and social isolation, among vulnerable populations in included neighbourhoods. Families want connection to one another and to resources but look to others to facilitate those connections. Families may want or need social connections but do not engage if it means sacrificing their values or sense of self-worth. These findings provide a deeper understanding of the factors that might allow us to disrupt social isolation by building relationships in communities that face social and health inequities.

Mass spectrometry-compatible silver staining.

INTRODUCTIONThe ammoniacal silver staining method is one of the most sensitive methods used to detect proteins on an SDS-PAGE gel. However, this and other standard silver staining methods are not compatible with mass spectrometry (MS), which is fast becoming the best way to identify proteins isolated on 2D gels. Because the proteins in gels to be analyzed by mass spectroscopy cannot be modified, many of the common sensitizing agents (e.g., glutaraldehyde and strong oxidizing agents) cannot be used. This method is compatible with MALDI and ESI-MS, and it shows an increased ability to deal with semipreparative protein loads without negative staining as compared with other silver staining methods. However, this process is less sensitive than standard silver staining methods.

Staining membrane-bound proteins with coomassie blue r250.

INTRODUCTIONCoomassie Blue R250 permanently stains membrane-bound proteins and is compatible with PVDF and nitrocellulose membranes, but it is incompatible with nylon membranes. This technique is relatively insensitive, with a detection limit of ~1.5 µg of protein. One drawback of Coomassie Blue staining is that it produces a high background that can make interpretation of results difficult.

Staining membrane-bound proteins with ponceau s.

INTRODUCTIONBecause Ponceau S is relatively insensitive (~1 µg of protein), only the most abundant proteins will be visible. However, it is a reversible stain that can be removed completely with H(2)O prior to processing the blots. After staining, a soft lead pencil can be used to record the presence of visible proteins and molecular-weight markers, which will help when aligning the proteins detected on the membrane by western analysis with those in a total protein-stained gel or membrane. Ponceau S is compatible with both nitrocellulose and PVDF membranes.

Staining membrane-bound proteins with colloidal gold.

INTRODUCTIONColloidal Gold is the most sensitive staining technique for proteins bound on membranes, detecting as little as 1-3 ng of protein. Protein spots are permanently stained a dark red after incubation with the Colloidal Gold solution. Colloidal Gold staining can detect proteins on both nitrocellulose and PVDF membranes, but it is not recommended for nylon membranes.

Preparative 2D Gel Electrophoresis with Immobilized pH Gradients: SDS-PAGE of Proteins.

INTRODUCTIONFollowing first-dimension IEF and equilibration of the IPG gel strips, the proteins are separated on the basis of their molecular weight in the second dimension on an SDS-PAGE gel. Systems for this separation are available from a variety of suppliers and are commonly found in many protein chemistry laboratories. This protocol describes a method for placement of the IPG strip and gives some recommended electrophoresis conditions for these second-dimension gels.

Preparative 2D Gel Electrophoresis with Immobilized pH Gradients: Rehydration of IPG Strips for Isoelectric Focusing of Proteins.

INTRODUCTIONThis protocol describes a method for rehydration of IPG gel strips in preparation for their use for isoelectric focusing (IEF) on immobilized pH gradient (IPG) gels. Following rehydration, IEF can be performed using either a flatbed unit or a self-contained instrument.

Preparative 2D Gel Electrophoresis with Immobilized pH Gradients: Isoelectric Focusing of Proteins in a Multipurpose Flatbed Electrophoresis Unit.

INTRODUCTIONThis protocol describes a method for separating proteins based on their net charge using the technique of isoelectric focusing (IEF) on immobilized pH gradient (IPG) gels. This method serves as the first dimension of the 2D separation. The method described in this protocol utilizes a flatbed unit; however, self-contained instruments for IEF are also available.

Preparative 2D Gel Electrophoresis with Immobilized pH Gradients: IEF of Proteins in an IEF-Dedicated Electrophoresis Unit.

INTRODUCTIONThis protocol describes a method for separating proteins based on their net charge using the technique of isoelectric focusing (IEF) on immobilized pH gradient (IPG) gels, providing the first dimension of the 2D separation. In this protocol, the IPG gels are focused using self-contained instruments for IEF. These high-voltage systems allow fewer manipulations of the IPG gels, resulting in less error, strip mix-up, contamination, air contact, or urea crystallization. Because rehydration and IEF can be performed consecutively within a single unit, these two steps can be performed unattended overnight. Finally, faster separations and sharper focusing are possible due to the higher voltage available in these instruments.

Phosphoprotein Staining with the GelCode Phosphoprotein Staining Kit.

INTRODUCTIONThe phosphorylation state of a protein has an important role in the regulation of a wide variety of cellular processes. As a result, there has been a great deal of interest in detecting phosphorylated proteins. The method presented here uses the GelCode phosphoprotein staining kit (Pierce Chemical Company). This method depends on the hydrolysis of the phosphoprotein phosphoester linkage using sodium hydroxide in the presence of calcium ions. The gel containing the newly formed insoluble calcium phosphate is then treated with ammonium molybdate in dilute nitric acid. The resultant insoluble nitrophospho-molybdate complex is stained with Methyl Green. After destaining, the phosphoproteins are colored green to green-blue. The detection limit is in the nanogram range, but depends on the degree of phosphorylation of the protein. This method will detect the phosphoproteins phosvitin and ß-casein in the 40-80 ng/band and 80-160 ng/band range, respectively. The method presented here is for staining minigels. Volumes will need to be increased for larger gels.

Preparation of Vertical SDS Slab Gels: Casting a Single Homogeneous Gel.

INTRODUCTIONFollowing the separation of proteins by IEF, the second dimension is carried out by SDS-PAGE. This protocol details the method for casting single homogeneous SDS-PAGE gels. Homogeneous gels (with the same %T and %C throughout) offer the best resolution for a particular molecular-weight range and are commonly used because they are the easiest to pour reproducibly. The second-dimension gels can be conveniently prepared in three different formats (i.e., sizes): minigels, for use with 7-cm IEF first-dimension gels; standard gels, for use with 11-, 13-, and 18-cm IEF first-dimension gels; and large-format gels, for use with 18- and 24-cm IEF first-dimension gels. All of the gels use a common set of reagents, listed below, but differ slightly in the equipment required.

Preparation of Vertical SDS Slab Gels: Simultaneous Casting of Multiple-Gradient Gels.

INTRODUCTIONGradient SDS-PAGE gels provide the best resolution over a wide range of molecular weights, resulting in sharper protein spots, because diffusion is minimized by the decreasing pore size in the gel. However, gradient gels are more difficult to produce reproducibly; thus, they are commonly cast with multiple-gel casters, which allows for an identical set of gels to be produced for an experiment. Presented here is a method for casting gradient gels using a multiple-gel casting system.

Preparative 2D Gel Electrophoresis with Immobilized pH Gradients: IPG Strip Equilibration.

INTRODUCTIONThe equilibration step serves to saturate the IPG strip with the SDS buffer system required for the second-dimension separation. The equilibration solution consists of buffer, urea, glycerol, reductant, SDS, and dye. The buffer (50 mM Tris-HCl, pH 8.8) maintains the appropriate pH range for electrophoresis. Urea and glycerol are added to reduce the effects of electroendosmosis, thus helping improve protein transfer from the IPG strip to the second dimension. The reductant (dithiothreitol) ensures that disulfide bridges are broken. SDS ensures that the proteins are denatured and also provides a net negative charge to all proteins. Iodoacetamide, introduced during a second equilibration step, alkylates thiol groups on the proteins, preventing their reoxidation during electrophoresis, and thus reducing streaking and other artifacts in the second-dimension separation. Iodoacetamide also alkylates residual dithiothreitol, preventing point streaking and other silver staining artifacts. Finally, a tracing dye (bromophenol blue) is added to allow the electrophoresis to be monitored during the run.