Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.

Pre-labeled protein standards useful in electrophoresis that have sharp, consistent separation characteristics that are substantially the same as those of their unlabeled counterparts are provided. The invention provides pre-labeled protein standard sets that include a plurality of labeled proteins that are labeled on a first amino acid, in which side reactions of the label with amino acids not targeted for labeling are reduced.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

The disclosure provides methods and kits for diagnosing the nutritional state of selenium, using six proteins as biomarkers for which the expression increases when the metabolic state is supra-nutritional.

The disclosure provides methods and kits for diagnosing the nutritional state of selenium, using six proteins as biomarkers for which the expression increases when the metabolic state is supra-nutritional.

An apparatus includes a body portion that defines a reservoir and a set of substantially flexible capillaries. The set of substantially flexible capillaries are fixedly coupled to the body portion and in fluid communication with the reservoir. A connector is configured to be coupled to the body portion to be in fluid communication with the reservoir and the set of substantially flexible capillaries. The connector is further configured to be coupled to a vacuum source. The apparatus is arranged such that at least a part of the body portion is electrically conductive. Methods for separating and detecting an analyte from a biological sample with the apparatus are also provided. For example, methods for separating and detecting one or more proteins from a cellular lysate or a purified protein are also provided.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

Some embodiments described herein relate to a method that includes separating an analyte-containing sample via electrophoresis in a capillary. The capillary is loaded with a chemiluminescence agent, such as luminol, that is configured to react with the analyte (e.g., HRP-conjugated proteins) to produce a signal indicative of a concentration and/or quantity of analyte at each location along the length of the capillary. A first image of the capillary containing the analytes and the chemiluminescence agent is captured over a first period of time. A second image of the capillary containing the analytes and the chemiluminescence agent is captured over a second, longer, period of time. A concentration and/or quantity of a first population of analytes at a first location is determined using the first image, and a concentration and/or quantity of a second population of analytes at a second location is determined using the second image.