Distance control during injection

For microinjection and subsequent analysis (e.g. by time-lapse microscopy), cells are plated on 35 mm dishes with coverglass bottoms (MatTek Corp., Ashford, MA, USA), that allow for the use of high numerical aperture, short distance objectives. During injection and time-lapse microscopy, cells are incubated in tissue culture media preferably without phenol red and only low concentrations of serum (1%) to keep background fluorescence from the culture medium to a minimum. To keep the pH stable, carbonate-free culture medium (Gibco) buffered with 20 mM Hepes pH 7.4 is used. Temperature is kept at 37 °C, for example by enclosing the entire microscope and microinjection manipulators in a temperature controlled Perspex box. 

Distances can be controlled during injection molding. Control of distances is critical to producing high quality products at alow cost because longer distances result in longer cycle times. The most common distances are used for mold close, dosage or shot size, cushion or pad, screw return, mold open, and ejection. 

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