Abstract: Microfluidic devices and methods for analyzing glycan profiles of glycoproteins are provided. Some embodiments of the devices comprise a deglycosylation column for cleaving glycans, an optional cleaning column for removing proteins, a trapping column for enriching glycans, and a separation column for resolving glycans. The devices and methods significantly improve the speed and sensitivity of glycan analysis.

Abstract: Microfluidic devices and methods for analyzing glycan profiles of glycoproteins are provided. Some embodiments of the devices comprise a deglycosylation column for cleaving glycans, an optional cleaning column for removing proteins, a trapping column for enriching glycans, and a separation column for resolving glycans. The devices and methods significantly improve the speed and sensitivity of glycan analysis.

Abstract: A microfluidic device for glycan analysis includes a deglycosylation column comprising a glycosidase attached to a solid support; a tagging column comprising a reactive ester for reaction with an amino group, wherein the tagging column is arranged downstream of the deglycosylation column; an analytical column comprising a stationary phase capable of separating a derivatized glycan; and a plurality of inlet/outlet ports configured to connect with channels on a switching element to form flow paths.

Abstract: A microfluidic device for glycan analysis includes a deglycosylation column comprising a glycosidase attached to a solid support; a tagging column comprising a reactive ester for reaction with an amino group, wherein the tagging column is arranged downstream of the deglycosylation column; an analytical column comprising a stationary phase capable of separating a derivatized glycan; and a plurality of inlet/outlet ports configured to connect with channels on a switching element to form flow paths.

Abstract: MALDI sample holders and methods of using and making the same are provided. The MALDI sample holders are configured for use in matrix assisted laser desorption/ionization and include a planar substrate having a surface and at least one fluid retaining structure present on the surface. The fluid retaining structure includes a material that changes from a first fluid state to a second solid state in response to a stimulus. Also provided are methods of using the subject MALDI sample holders in a matrix-assisted laser desorption/ionization protocol, as well as methods of producing the subject MALDI sample holders. Kits for use in practicing the subject methods are also provided.

Abstract: Methods and devices for performing matrix assisted laser desorption/ionization protocols are provided. In accordance with the subject methods, an analyte is first deposited into a fluid retaining structure present on a substrate surface. The fluid retaining structure includes a material that changes from a first fluid state to a second solid state in response to an applied stimulus. The resultant retained analyte is then digested with an analyte-digesting reagent to produce fragments of the analyte. The resultant fragments are then ionized for subsequent mass spectrometry analysis. Also provided are devices, e.g., sample holders, suitable for use in the subject methods. Kits for use in the subject methods are also provided.

Abstract: A bioanalytic method replenishes depleted zones of a sample liquid in a shallow probe-array reaction cell under ultragravity centrifugal forces. The ultragravity overcomes viscous and surface-tension forces to permit replenishment despite a shallow reaction-cell depth of 25 microns. Thus, replenishment is achieved using {fraction (1/10)}th the sample volume normally used in probe-array systems that use mixing to facilitate binding reactions. For similar amounts of sample, the shallow cell takes advantage of a ten-times greater concentration to achieve much greater signal strengths in much shorter times. Thus, signal strengths that normally take 17 hours to achieve are achieved in about 60 minutes.