Cleaning and Sterilizing Reusable Acrylic Instruments
Please see warnings for additional information on caring for reusable instruments.
Cleaning After Each Use
Neuro Probe precision-machined acrylic instruments should be handled and washed individually. Hard objects, including the hardware mounted in the bottom plate, should not be allowed to bang into the sealing surfaces of the chamber.
- Soak components in distilled or de-ionized water without delay after each use, to prevent proteins from drying on the instrument. The chamber can be reused immediately.
- To clean after use rinse all parts in running distilled or de-ionized water.
- Remove residual water from each well in the bottom plate with a disposable pipette tip on a suction line, and let chamber components air dry at room temperature under a protective paper towel, or blow dry with Clean compressed gas, e.g. nitrogen.
Proteins and other contaminants sometimes accumulate on the walls of the wells in the chamber and on the gasket. This can happen quickly depending on the nature of the solutions used. Accumulation is immediate and severe if protein solutions are ever allowed to dry in the wells. Periodic soaking of all the chamber components in Terg-a-Zyme® (an enzyme active detergent available from most major laboratory suppliers or contact Alconox, Inc.) for 1 to 3 hours at 60°C usually removes these residues. Follow with thorough rinsing under running distilled or de-ionized water and soaking in same overnight. Chambers can be cleaned this way as often as necessary; even weekly cleanings will not damage the chamber.
If continued contamination is indicated by the presence of erratic results, or by negative controls migrating faster than normal, the gasket is often the source of the problem. The gasket should be soaked in hot Terg-a-Zyme at 100°C and ultrasonically cleaned if possible. The gasket is heat and scratch resistant, but very sensitive to solvents, which make it swell. A pipe cleaner may be used in the holes of the gasket (but not the chamber). If problems persist after this treatment, we recommend two courses of action. First run some controls in blind well chambers parallel to the multiwell chamber. Since blind well chambers don't use gaskets, this will help determine if the gasket in your multiwell is contaminated. Second, keep a spare gasket on hand and replace the old one.
If sterilization is required due to the presence of pathogens or for studies with long incubation times, acrylic and metal components may be sterilized in one of three ways:
- gas sterilization with ethylene oxide
- soaking for 30 to 60 minutes in 1 molar sodium hydroxide at 60°C, followed by thorough rinsing in sterile de-ionized water in a sterile environment
- soaking in weak chlorine solution (1 T Clorox® to a gallon of distilled or de-ionized water) for 30 to 60 minutes, followed by soaking in sterile de-ionized water in a sterile environment. This will usually kill all bacteria. If other pathogens are present the strength and/or duration of the soak may need to be modified.
Acetal components (Boyden and blindwell retainers, MB-series latch hardware) will age rapidly with prolonged or repeated exposure to sodium hydroxide.
The gasket only can be autoclaved or boiled in de-ionized water. Avoid immersing the gasket in chlorine or sodium hydroxide solutions; it will absorb, and later bleed, these solutions.