How To Handle Caenorhabditis Elegans Microinjection? Don’t Miss The Step-by Step Details! Background of C. elegans Microinjection Caenorhabditis elegans (C. elegans) is an important model organism used for studying animal genetics, ontogeny, and ethology. It can help us to study the mechanism of action from molecular and cellular level to system biological level in regard to the corresponding life cycle. Microinjection technology provides a capillary glass tube with a tip diameter of millimeters for the injection of nucleic acids into the worm’s gonad that is subsequently absorbed by the egg cells and generated into the form of extrachromosomal arrays. C. elegans microinjection is the core technique in the C. elegans research paradigm. It is widely used in studying gene expression, gene function and genetic interactions inside the body of c elegans. Workflow of C. elegans Microinjection as shown in the figure C. elegans Microinjetion Protocol Step 1: Preparation of agar plates Drop 50ul of 2% hot agarose solution on a 24 × 60 mm glass coverslip and gently put another coverslip on top (beware of the air bubbles). After the flattened agarose solidifies (~5 min), you can remove the coverslip on top by gently sliding. Let the agar plate dry overnight at room temperature or bake it at 80℃ for 1 hour. Stack the plates for later use.

Figure: Preparation of the agar plate[1]. A. Mount the coverslip on a clean working stage with 2 tapes. B. Drop 50ul of 2% hot agarose solution in the middle of the coverslip C. Place another coverslip on the agarose drop and gently press it to make it flattened. Remove the coverslip after the agarose solidifies. Step 2: Preparation of needles The needle is the key to successful C. elegans microinjection. RWD micropipette puller helps with generating two needles with stable and consistent performance. It is recommended to use RWD capillary glass tube for pipette pulling to fill up the tip of...

Figure: Worm mounted on the agar plate and prepared for injection. The arrows show the gonads selected for injection. The proportion is 50μm[1]. Step 6: Microinjection Place the agar plate on the mechanical stage. Find the worm under the microscope and focus on the gonad by adjusting the condenser lens. Use the RWD Micromanipulator to insert the needle into the gonad. Switch on the RWD Nanoliter Microinjection Pump to start injecting.

Figure: The flow of injection mix before (1) and after (2) microinjection. The arrow marks the gonad areas where the injection mix arrives[2]. Step 7: Worm recovery Add a few drops of buffer solution to the injected worm under the stereomicroscope. After 2-5 minutes, the worm will become active again. It should start swimming and moving its head from side to side. By then, you can transfer it back to the cell culture plates for regular cultivation at 20℃. Precautions[2] Agar plates: If the worm dies quickly on the agar plate, it is an indication of the plate being too dry. In this case, it can...