Quartet is a miniature fluorescence microscope and data collection software package optimized for neuronal calcium imaging.
Thin, cylindrical, graded-refractive-index lenses (GRIN) get implanted along with our specially designed , patent pending focus adjustable fiber-lens connector in ANY region of the brain and spinal cord. The image below is a representative of such a connector between the GRIN lens on the bottom left and fiber optics on the top right. The coin is an American dime.
The imaging fiber bundle connects to the implanted GRIN lens to transmit the fluorescence signal from neurons to the CMOS sensor. Quartet uses FOUR optical imaging fiber bundles and comes with four such highly flexible and light weight lens connectors. Each bundle includes 18000 single fibers, each of which are 7.5micron in diameter.
After connecting the fiber to the lens, the user manually finds the best focus using a key that we provide with Quartet. The design of the connector is such that even when the fiber probe is disconnected the initially set focus remains the same. This ensures the same plane of neurons is imaged as days go by, ensuring any observed changes come from the changes in the neuronal micro-circuitry and not from focusing on a different plane of neurons. This is a capability essential for answering R&D questions about brain and spinal cord neuronal micro-circuitries.
We currently offer two types of GRIN lenses for imaging different areas of the central nervous system. In the picture below, the lens that is in the connector on the top, held by the scientist, is 0.7mm in diameter and more than 8mm long to reach any area of the brain in rodents or larger animals. The lens in the connector near the ruler is 1mm in diameter and can reach areas in the brain which are up to 2.5mm deep.
Software allows users to obtain and save images from the microscope. Each frame is time-stamped with the time automatically recorded in the file name.
Manual selection of neurons allows extraction of neuronal activity for each chosen neuron.
Save trace generates a .png file displaying neuron locations
The traces are then saved in a cvs file for analysis