骨头中成分检测方案(研磨机)

智能文字提取功能测试中

Your Science is Our Passion@ HOW TO GUIDELINES Guidelines for Cryogenic Grinding of Bone in SPEX SamplePrepFreezer/Mills Any plant or animal tissue can be ground in a SPEX Freezer/Mill， and this includes all bone： fresh oraged， wet or dry. Freezer/Mill grinding vials are immersed in liquid nitrogen (LN) before and duringgrinding， first to make the sample brittle enough to grind， and then to keep it brittle during theactual grinding. The actual grinding is done by a rod-shaped steel impactor that is magneticallyshuttled back and forth between two steel end plugs. Success in Freezer/Mill cryo-grinding depends on two main things： ：： The sample must be cold enough to be brittle. ：： The impactor must be able to move freely back and forth. The quantity of sample per load and the size of the sample pieces can heavily affect the grindingefficiency of the mill， particularly with bone， which can be very tough. A simple test is to load thevial， then shake it back and forth to make sure the impactor can move from end to end of the vial. Ifthe sample pieces are too large or there is too much sample in the vial， the impactor can jam， or notmove far enough to grind effectively. In extreme cases， if the impactor is deflected sideways orwedged against the polycarbonate cylinder by a large piece of bone， the cylinder can crack orbreak. To grind bone in the standard 6751 vial， we recommend cutting it before grinding into piecesapproximately 5 mm in diameter， or smaller. The quantity to be ground in a 6751 Vial can vary fromless than half a gram up to four or five grams， depending on the toughness of the sample and thesize of the pieces. The optimum sample size and quantity for your samples should be determinedempirically. It may be possible to grind one or two large pieces of bone at a time - for example， a 2-gram chunk in one end of the vial- but the uniformity of the results will be better and there will bemuch less risk of cracking a cylinder if the bone is cut into smaller pieces first. For bone in the 6751 vial we recommend at least 10 minutes of Pre-Cool time. Depending on thequantity and size of the bone pieces， grinding can take anywhere from 1 minute to 10 minutes.Grinding times longer than 2 minutes should be split into 2- minute grinding periods separated by2 minutes of cooling. Grinding can be speeded up by increasing the grinding rate from the factorysetting of 10 to as much as 14 or 15. If the 6751C polycarbonate center cylinders persist in cracking or breaking， we recommend the useof the 6752 steel center cylinders. These do not form a tight seal with the end plugs when chilled(as do the polycarbonate cylinders)， and the joints between the end plugs and steel cylinder shouldbe sealed by a piece of Teflon plumber's tape wrapped around the shank of each end plug.The large 6801 vial can grind up to 40 or 50 grams of bone， and the size of the pieces is notimportant unless they are large enough to prevent the impactor from moving. However， the 6801vial usually takes longer to grind a sample than the 6751 vial， and for a large sample we recommend15 minutes of pre-cooling. As with the 6751 vial， grinding should be programmed for two minutes TissueHomogenizationCell LysisGrinding &Pulverizing Grinding Bone in the Freezer/Mill ：：APPARATUS：Freezer/Mill SPEX SamplePrep. 2 Dalston GardensStanmore，HA7 1BQ， UKTel：+44 (0)20 8204 6656Fax： +44 (0)208204 6654 E-mail：sales@spexcertiprep.co.uk Web： www.spexcertiprep.co.uk on and two minutes of cooling for as many cycles as necessary to grind the bone to the desiredparticle size range. The grinding rate can be left at the factory setting of 10 or increased until theimpactor starts to "stutter；" the maximum effective rate for the 6801 vial to run smoothly is usually12. Grinding performance in the Freezer/Mill is affected by the quantity of sample， the size of thesample pieces， and grinding time. To improve performance， decrease the overall sample quantity，pre-cut the sample into smaller， more uniform pieces， or grind for additional cycles. 10 minutes ofpre-cooling for the 6751 vial and 15 minutes of pre-cooling for the 6801 vial ought to be enough forbone， but for very large pieces of bone in the 6801 you may need to increase the pre-cooling timeto 20 minutes. Again， we recommend running the Freezer/Mill for 2 minutes per grinding cycle with 2 minutes ofcooling between cycles， to let the sample and coil cool back down. It is possible to run theFreezer/Mill continuously， but as the coil heats up it becomes less efficient. Bone will probablyremain "grindable" for many minutes of continuous grinding， but for difficult-to-grind samples likesynthetic fibers and polymer sheets， it is probably better to keep them as cold as possible duringgrinding. 6970EFM Freezer/Mill Generally speaking， all components of Freezer/Mill vials can be cleaned with hot water anddetergent or soap， and decontaminated by dipping in a solution of 10% bleach or dilute mineralacids. After cleaning they should be dried. Polycarbonate cylinders can be damaged by excessiveheat (as in autoclaving) or exposure to organic solvents including alcohol. Steel impactors and endplugs， and steel cylinders， may be sterilized by disinfectants， alcohol， autoclaving， etc.， but shouldnot be left in contact with water and aqueous fluids for any length of time，as magnetic steel canrust under these conditions. SPEX SamplePrep7 6870 Freezer//Mill SPEX SampleFePrep For further advice about Freezer/Mill applications and maintenance， please call Customer Service at1-800-LAB-SPEX x465， or 732-549-7144x465. You can also contact us via email atsampleprep@spexcsp.com. SPEX CertiPrep，Ltd 2 Dalston Gardens Stanmore， HA7 1BQ， UK Tel：+44(0)20 82046656 Fax：+44(0)2082046654 E-mail：sales@spexcertiprep.co.uk Web：www.spexcertiprep.co.uk 使用SPEX Freezer Mill 冷冻研磨机研磨，可高效研磨骨头等坚硬材料，并确保分析材料一直处于零下196℃，保存被分析材料的生物活性不被破坏。