Rodent Brain Microinjection Using a Quartz Microneedle

Abstract

Source: Paolone, G., et al. Personalized Needles for Microinjections in the Rodent Brain. J. Vis. Exp. (2018).

This video demonstrates a rodent brain microneedle injection using a quartz microneedle with holes. The microneedle is attached to a syringe and micropump to control the delivery rate. The needle with the injection solution is inserted into the brain with the delivery speed set at low. Once positioned, the delivery speed is increased. The needle is withdrawn after a brief pause.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Preparation of Quartz Needles

1. Clean and sterilize the quartz capillaries (see Table of Materials) by placing them for 5 min in distilled water, 5 min in ethanol 99%, and 5 min in diethyl-ether.
2. Leave capillaries under the hood for at least 1 h to let them dry completely.
3. Prepare the needles using a laser puller according to parameters that allow the production of a sufficiently long, sufficiently thin needle, depending on the individual needs.
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Results

Figure 1: Microscopic image of a quartz needle tip, showing different diameters of the tip and holes emp.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Quartz capillaries	Sutter Instruments, Novato, CA USA	Q100-50-10	Without filament
Puller	Sutter	P2000
Micropipette storage jar	World Precision Instruments (WPI), Sarasota, FL, USA	E210
Laser microdissector	Leica Microsystems, Wetzlar, Germany	LMD6500
Hamilton syringe	Hamilton ILS Innovative Labor Systeme GmbH, StŸtzerbach, Germany	19138-U
Microinfusion pump	Univentor, Zejtun, Malta	Model 864
Manual microinjection pump kit	WPI	Item#: MMP-KIT	Kit allowing for micropipettes to be securely mounted to the stereotactic frame
Precision Drill	Proxxon	28510 MicroMot 50/E	Ball bearing drive shaft with variable speed
Artficial Cerebral Spinal Fluid	Tocris	3525
Needles 26 G Blunt and 30 G Bevel	Hamilton	26 G Blunt: 19138-U30 G Bevel: 20757