“E” “D” “C” A “F” “A” “B” DETAIL A this problem with two extra beveled surfaces. The tip of a single surface beveled tip is actually a blade instead of a point. It dulls very quickly. In contrast, the tri-surfaced tip has a real point. It not only penetrates much better but is also much more durable. Our tests show that our 33 gauge, 25 degree beveled tip penetrates easier and lasts longer than other manufacturers’ 33 gauge, 10 degree single beveled tips. With a 35 gauge tri-surface beveled tip, the resistance to the penetration becomes even less. Each of our tips undergo a penetration test before leaving the factory to guarantee the best results for our customers. Tip Order Number NF33BV-2 NF34BV-2 NF35BV-2 NF36BV-2 NFQ34-5 NF33BL-2 NF34BL-2 NF35BL-2 NF36BL-2 Silflex NF26BV-2 Tip Total Tip O.D. Tip I.D. Length Length “A” “B” “D” “C” 210 μm 185 μm 135 μm 110 μm 160 μm 210 µm 185 µm 135 µm 110 µm 460 µm 115 μm 85 μm 55 μm 35 μm 100 μm 115 µm 85 µm 55 µm 35 µm 100 µm 110 µm 3 mm 10 mm 5 mm 5 mm 3 mm 55 mm 10 mm 5 mm 5 mm 3 mm 40 mm 35 mm 35 mm 33 mm 75 mm 34 mm 29 mm 29 mm 27 mm 35 cm 40 mm Total Shank Bevel O.D. Length Dead “E” “F” Volume 460 μm 460 μm 460 μm 460 μm 460 μm 460 µm 460 µm 460 µm 460 µm 460 µm ≈348 µm ≈290 µm ≈204 µm ≈156 µm n/a ≈348 µm ≈290 µm ≈204 µm ≈156 µm 0.416 µL 0.199 µL 0.435 µL 0.340 µL 0.589 µL 0.416 µL 0.199 µL 0.435 µL 0.340 µL 2.749 µL 0.380 µL Tip Material Stainless Steel Stainless Steel Stainless Steel Stainless Steel Quartz Stainless Steel Stainless Steel Stainless Steel Stainless Steel PUMPS, MICROINJECTION Available Tips 33 gauge: This tip is similar to Hamilton’s 7762 and 7803 series removable needles in both tip length and outer diameter. However, our beveled tip version is shorter, more durable, and penetrates better due to the special tri-surface grinding technique. In the past, 33 gauge tips were the smallest size sold by other manufacturers and were frequently cited in literature. However, our new 35 gauge tip is much better for injections involving small animals, especially mice. Compared with Hamilton’s 33 gauge, 10 degree beveled tip, our 35 gauge 25 degree beveled tip can reduce the depth of penetration by almost 80%. The distance between the tip and the upper rim of the opening (dimension F on the drawing) is 348 microns for the 33 gauge tip. The distance for our 35 gauge tip is only 230 microns. In addition, the smaller tip size significantly reduces the required penetration force. In nearly all applications, a 33 gauge tip can be replaced with our 35 gauge tip and produce better results. 34 gauge: This is a transitional size between the 33 gauge and 35 gauge. If the 35 gauge is too weak and the 33 gauge is too large, this makes a good alternative. 35 gauge: This was the most popular and preferred tip of most scientists during our field trial. The combination of its strength, length, durability, and clogging resistance creates a balance with very little compromising of the individual properties. It is much smaller than the 33 gauge tip offered by other manufacturers. It is only slightly larger than the 36 gauge tip but is much stronger and less likely to be clogged. Samples can be directly loaded with this tip. Its 5 mm length is sufficient enough for almost all injection applications in mice. 36 gauge: This is the smallest tip that is commercially available. The tip is so small that it can be inserted into the opening of the 33 gauge needle tip. Because this is pushing the limits of what current technology can produce, there are some limitations to consider before using. Its thin diameter makes it necessary to limit its length to 2.5 to 3 mm in order to maintain a usable strength. Since the tip ID is in the 25 to 50 micron range, it is very easily clogged. Therefore, only well filtered solutions can be used. Depending on the viscosity of the sample, the user might also need to pre-load the syringe with a regular tip before switching to this tip for injection. We recommend using the 35 gauge tip instead of the 36 gauge unless it is absolutely necessary. Flexible Quartz Tubing: The flexible quartz tubing tip is made of 160 micron OD polyimide coated quartz tubing with a special adapter sleeve mounted at the end. It is designed for filling glass capillary electrodes or pipettes, just like WPI’s traditional MF34G Microfil. However, unlike the traditional MicroFil, which has about 50 microliters of dead volume in its luer hub, the dead volume of this tip is less than 0.4 microliters. It is useful for loading electrodes with solutions that have a limited volume or are too expensive to waste. NANOFIL NEEDLES NF33BL-2 33 G blunt NanoFil needle (pkg of 2) NF34BL-2 34 G blunt NanoFil needle (pkg of 2) NF35BL-2 35 G blunt NanoFil needle (pkg of 2) NF36BL-2 36 G blunt NanoFil needle (pkg of 2) NF33BV-2 33 G beveled NanoFil needle (pkg of 2) NF34BV-2 34 G beveled NanoFil needle (pkg of 2) NF35BV-2 35 G beveled NanoFil needle (pkg of 2) NF36BV-2 36 G beveled NanoFil needle (pkg of 2) NF33-36BL Assortment of 4 blunt NanoFil needles NF33-36BV Assortment of 4 beveled NanoFil needles REPLACEMENT PARTS & ACCESSORIES NFINHLD NanoFil Injection Holder SILFLEX-2 SilFlex tubing 35 cm long (pkg of 2) (dead volume = 2.74 µL) NFGSK-5 Spare Silicone Gasket for NanoFil & Holder (pkg of 5) NFQ34-5 34 Gauge Flexible Quartz Tubing for filling (pkg 5) UK: Tel: +44 (0)1462 424700 • wpiuk@wpi-europe.com World Precision Instruments www.wpiinc.com Germany: Tel: +49 (0)30-6188845 • wpide@wpi-europe.com US: Tel: 941-371-1003 • sales@wpiinc.com 179