- CAP PIERCING
- SURFACE CONTROL
- HEATING PROBES
- SAMPLING PRECISION
- ASSEMBLING TECHNIQUES
Cap piercing brings challenges in terms of strength, resistance to wear, venting and non-coring tips.
- Column strength can be improved by the choice of a cobalt-chromium alloy and by a strong assembly between the tubular pipette and its collet, such as laser welding or brazing.
- Resistance to wear with a surface modification such as a coating (hard chromium, TiN, DLC) or an ion implantation (kolsterisation)
- Venting may be achieved through longitudinal machined groves, multi-lumen tubing or by separating the functions with a sampling probe circulating inside a piercing needle
Non coring tips may be pencil points, side-cut or specific bevels
Contamination or carry-over is the process by which materials are carried into a reaction mixture where they do not belong.
Materials can be the sample, the reagent, or ions leaching from the probe metal. Contamination is often a major problem with fixed reusable tips, a complex issue that also involves the instruments pipetting and washing procedures as well as the nature of the liquids and the sensitivity of the tests.
Probe induced contamination can be minimized through the choice of the base material and the best tube drawing technique to minimize the tubing surfaceroughness. Surface properties may be further enhanced with passivation, electropolishing, coatings or fluoropolymer lining.
Electropolishing, dynamic passivation, buffing, honing, large choice of coatings…
The inside surfact finish control enables unique performances in critical applications such as IVD probes.
Rising temperature within the pipetting probe can be achieved through a water jacket or a resistive layer (printed circuit or wound wire) with thermostatic regulation using miniature thermistors.
Heating is usually applied indirectly to the pipette tubing through a higher mass component in a good conductivity material, such as copper or aluminum.
A patented design based on resistive layer can heat the smallest volume down within the probe tip.
SAMPLING PRECISION & REPEATABILITY
Sampling precision and repeatability are affected by the geometry and the surface of the pipetting tips…
Tapered tips are designed according to the sampling volumes; Minitubes has developed a proprietary process to obtain very smooth ID surfaces on the cylindrical portions and on the transition cones, with no limitation on the stepped lengths.
Sampling repeatability is linked with the tip manufacturing process variability;
Tip geometry and surface properties affect the sample / pipette contact surface and may influence droplet formation.
Minitubes masters a vast range of assembly techniques…
Laser, plasma, TIG and electric welding, high and low temperature soldering, mechanical adjustment, crimping, glueing….
Because we manufacture the tube, parts and assemblies, we are the only contact you need, even for the most complex assemblies.
Countless tubular component possibilities: from cutting to length to intricate assemblies.