密度標(biāo)記珠是已知質(zhì)量密度的小色微球，用于校準(zhǔn)密度梯度并確定梯度色譜柱的密度。密度梯度通常用于細(xì)胞，病毒和亞細(xì)胞顆粒的分離和純化。通常使用覆蓋一定密度范圍的一組密度標(biāo)記珠。

梯度是用在柱內(nèi)不同高度漂浮的珠進行校準(zhǔn)的。當(dāng)一個測試樣品被添加到色譜柱中時，它會下降到中性浮力點，密度由校準(zhǔn)圖確定。密度梯度柱可用于測量任何樣品的密度。

化合物密度標(biāo)記珠在2.5ml小瓶中以20％濃度提供在水溶液中。我們的密度珠粒尺寸在200-300um之間。與已停產(chǎn)的GE醫(yī)療保健套件不同，Cospheric的彩色微球已準(zhǔn)備就緒，可直接使用。

運輸：DMB產(chǎn)品不需要特殊運輸。

儲存：由于沒有添加防腐劑，我們建議在批次編號為[YYMMDD-XXX]的6個月內(nèi)使用非冷藏產(chǎn)品。該產(chǎn)品可以冷藏或冷凍以延長溶液保質(zhì)期。密度珠是惰性的，不會降解。但是，該解決方案可能降解導(dǎo)致結(jié)塊和懸浮不良，從而導(dǎo)致更寬的頻帶。如果溶液降解，可以將珠子沖洗干凈，然后使用我們的Tween懸浮方案重新懸浮。

Density marker beads are small colored microspheres of known mass density that are used for calibrating density gradients and determining density in gradient columns. Density gradients are often used for separations and purification of cells, viruses and sub-cellular particles. Generally a set of several density marker beads covering a range of densities is used. 

The gradient is calibrated with beads that float at different heights within the column. When a test sample is added to the column it drops until the point of neutral buoyancy and the density is determined from the calibration chart. Density gradient columns can be used to measure the density of any sample.

Cospheric Density Marker Beads are provided at a 20% concentration in an aqueous solution in 2.5ml vials. Our Density Beads are in the 200-300um size range. Unlike GE Healthcare kits that have been discontinued, the Cospheric's colored microspheres are ready for use right out of the vial.

Shipping: DMB product does not require special shipping.

Storage: As no preservatives are added, we recommend unrefrigerated product to be used within 6 months of date coded lot# [YYMMDD-XXX]. The product can be refrigerated or frozen to extend the solutions shelf life. The density beads are inert, and do not degrade. However, the solution can degrade causing agglomeration and poor suspension, leading to wider bands. If the solution degrades, the beads can be flushed clean, and then re-suspended using our Tween Suspension Protocol.

Item #                 Description/Size 

DMB-kit                 Density Marker Beads Kit of 6 Vials (1.02, 1.04, 1.06, 1.08, 1.09, 1.13g/cc)

DMB-FGRN-1.02 2.5ml      Density Marker Beads for Density Gradients, Fluorescent Green Microspheres, 1.02g/cc, 20% concentration in Aqueous Solution

DMB-FORG-1.04 2.5ml      Density Marker Beads for Density Gradients, Fluorescent Orange Microspheres, 1.04g/cc, 20% concentration in Aqueous Solution

DMB-FVIO-1.06 2.5ml      Density Marker Beads for Density Gradients, Fluorescent Violet Microspheres, 1.06g/cc, 20% concentration in Aqueous Solution

DMB-RBLU-1.08 2.5ml      Density Marker Beads for Density Gradients, Dark Blue Microspheres, 1.08g/cc, 20% concentration in Aqueous Solution

DMB-FRED-1.09 2.5ml      Density Marker Beads for Density Gradients, Fluorescent Red Microspheres, 1.09g/cc, 20% concentration in Aqueous Solution

DMB-FBLU-1.13 2.5ml Density Marker Beads for Density Gradients, Fluorescent Blue Microspheres, 1.13g/cc, 20% concentration in Aqueous Solution