Abstract: The presently-disclosed subject matter includes fluorescent protein-based indicators for detecting ions, small molecule analytes, or combinations thereof. In some embodiments the indicators include a polypeptide, which itself includes a fluorescent polypeptide, a compound-binding polypeptide, and a polypeptide target of the compound-binding polypeptide. In some embodiments the polypeptide includes an EosFP polypeptide, a calmodulin polypeptide, and a M13 polypeptide, or fragments and/or variants thereof. The presently-disclosed subject matter also includes methods for detecting calcium in a sample with embodiments of the present polypeptides. In some embodiments the present indicators experience a permanent shift from green to red fluorescent when exposed to an detecting substance, such as calcium.

Abstract: The present disclosure provides, inter alia, genetically encoded recombinant peptide biosensors comprising analyte-binding framework portions and signaling portions, wherein the signaling portions are present within the framework portions at sites or amino acid positions that undergo a conformational change upon interaction of the framework portion with an analyte.

Abstract: Protein indicators useful for calcium imaging, in particular, red genetically-encoded calcium indicators (GECIs) disclosed herein rival best-of-class green GECIs in terms of sensitivity for detecting neural activity, and can be monitored in vivo. The presently-disclosed subject matter further includes a method of monitoring cell activity comprising stimulating a cell comprising a red GECI polypeptide; and detecting fluorescence emitted by the cell.

Abstract: A microtome includes a blade located at an end of a trough that defines a cavity for holding a liquid; a sample block in which the at least one sample is suspended, the sample block is moveable relative to the blade such that when the sample block is passed across the blade a section is cut from the sample block; a plate that includes a support frame that defines an opening, and a transparent film extending across the opening, the transparent film being transparent to electrons, a grasper being configured to receive and retain the plate, wherein the grasper is moveable relative to the blade; and a pusher section that lacks the sample pusher section.

Abstract: An apparatus includes a light source configured for generating a coherent light beam having a wavelength, ?, a light detector, and beam-forming optics configured for receiving the generated light beam and for generating a plurality of substantially parallel Bessel-like beams directed into a sample in a first direction. Each of the Bessel-like beams has a fixed phase relative to the other Bessel-like beams. Imaging optics are configured for receiving light from a position within the sample that is illuminated by the Bessel-like beams and for imaging the received light onto the detector. The imaging optics include a detection objective having an axis oriented in a second direction that is non-parallel to the first direction, where the detector is configured for detecting light received by the imaging optics. A processor configured to generate an image of the sample based on the detected light.

Abstract: This disclosure provides methods for identification of olfactory sensosry neurons (OSN) that recognize specific odorants. The method comprises introducing into the OSN, a permanent activity marker which exhibits a detectable and permanent change upon activation of the neuron in response to an odorant and exposure to an exteranal stimulus, such as light. The OSN can be isolated and its receptor characterized.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: Genetically encoded calcium indicator (GECI) polypeptides and the nucleic acid molecules encoding such polypeptides are provided. In addition, methods of using such nucleic acids and polypeptides in methods of screening for agonists or antagonists of G-protein coupled receptor (GPCR) or ion channels and methods of monitoring neural activity also are provided.

Abstract: The present disclosure provides, inter alia, genetically encoded recombinant peptide biosensors comprising analyte-binding framework portions and signaling portions, wherein the signaling portions are present within the framework portions at sites or amino acid positions that undergo a conformational change upon interaction of the framework portion with an analyte.

Abstract: The presently-disclosed subject matter includes azetidine-substituted fluorescent compounds, where the compounds may be used as probes, dyes, tags, and the like. The presently-disclosed subject matter also includes kits comprising the same as well as methods for using the same to detect a target substance.

Abstract: A microscope has a light source for generating a light beam having a wavelength, ?, and beam-forming optics configured for receiving the light beam and generating a Bessel-like beam that is directed into a sample. The beam-forming optics include an excitation objective having an axis oriented in a first direction. Imaging optics are configured for receiving light from a position within the sample that is illuminated by the Bessel-like beam and for imaging the received light on a detector. The imaging optics include a detection objective having an axis oriented in a second direction that is non-parallel to the first direction. A detector is configured for detecting signal light received by the imaging optics, and an aperture mask is positioned.

Abstract: A microscope has a light source for generating a light beam having a wavelength, ?, and beam-forming optics configured for receiving the light beam and generating a Bessel-like beam that is directed into a sample. The beam-forming optics include an excitation objective having an axis oriented in a first direction. Imaging optics are configured for receiving light from a position within the sample that is illuminated by the Bessel-like beam and for imaging the received light on a detector. The imaging optics include a detection objective having an axis oriented in a second direction that is non-parallel to the first direction. A detector is configured for detecting signal light received by the imaging optics, and an aperture mask is positioned.

Abstract: A system for a laser-scanning microscope includes an optical element configured to transmit light in a first direction onto a first beam path and to reflect light in a second direction to a second beam path that is different from the first beam path; a reflector on the first beam path; and a lens including a variable focal length, the lens positioned on the first beam path. The lens and reflector are positioned relative to each other to cause light transmitted by the optical element to pass through the lens a plurality of times and in a different direction each time. In some implementations, the system also can include a feedback system that receives a signal that represents an amount of focusing of the lens, and changes the focal length of the lens based on the received signal.

Abstract: The present disclosure provides, inter alia, genetically encoded recombinant peptide biosensors comprising analyte-binding framework portions and signaling portions, wherein the signaling portions are present within the framework portions at sites or amino acid positions that undergo a conformational change upon interaction of the framework portion with an analyte.

Abstract: Protein indicators useful for calcium imaging, in particular, red genetically-encoded calcium indicators (GECIs) disclosed herein rival best-of-class green GECIs in terms of sensitivity for detecting neural activity, and can be monitored in vivo. The presently-disclosed subject matter further includes a method of monitoring cell activity comprising stimulating a cell comprising a red GECI polypeptide; and detecting fluorescence emitted by the cell.

Abstract: An electron microscope specimen sample holder including a thin sheet base member with a first surface and an opposing second surface, the first surface defining a seat and support surface for a specimen holding film held by the sample holder, the base member including an aperture through the second surface exposing the holding film held by the sample holder, and including a grip engagement zone defined at least on part of the first surface arranged to engage a gripping device, and wherein at least one of the first or second surface has machine readable structures formed thereon arranged in patterns embodying data that defines at least one predetermined characteristic of the sample holder.

Abstract: Genetically encoded calcium indicator (GECI) polypeptides and the nucleic acid molecules encoding such polypeptides are provided. In addition, methods of using such nucleic acids and polypeptides in methods of screening for agonists or antagonists of G-protein coupled receptor (GPCR) or ion channels and methods of monitoring neural activity also are provided.

Abstract: The presently-disclosed subject matter includes fluorescent protein-based indicators for detecting ions, small molecule analytes, or combinations thereof. In some embodiments the indicators include a polypeptide, which itself includes a fluorescent polypeptide, a compound-binding polypeptide, and a polypeptide target of the compound-binding polypeptide. In some embodiments the polypeptide includes an EosFP polypeptide, a calmodulin polypeptide, and a M13 polypeptide, or fragments and/or variants thereof. The presently-disclosed subject matter also includes methods for detecting calcium in a sample with embodiments of the present polypeptides. In some embodiments the present indicators experience a permanent shift from green to red fluorescent when exposed to an detecting substance, such as calcium.

Abstract: Excitation light is focused to a focus within a sample and the focus is scanned within a volume in the sample with scanning optical elements. Signal light emitted from the focus is de-scanned, with the one or more scanning optical elements, onto a wavefront sensor as the focus is scanned within the volume. Based on the descanned signal light, an average aberration created by the volume of the sample of a wavefront of the excitation light is determined. A wavefront of the excitation light is corrected by an amount according to the determined average aberration while the focus is scanned within the volume, the signal light is imaged onto a photosensitive detector as the focus is scanned within the volume, and a wavefront of the imaged signal light is corrected by an amount according to the determined average aberration while the focus is scanned.

Abstract: Genetically encoded calcium indicator (GECI) polypeptides and the nucleic acid molecules encoding such polypeptides are provided. In addition, methods of using such nucleic acids and polypeptides in methods of screening for agonists or antagonists of G-protein coupled receptor (GPCR) or ion channels and methods of monitoring neural activity also are provided.