Allied Telesis 6870 manual section, Loading Samples into Freezer/Mill Vials

Note that there are three different sizes of vial that can be run in the 6870 Freezer/Mill: Large, Mid-Size, and Small. Mid-Size vials must be run with a 6886 Adapter in the coil, and Small vials must be run with a 6806 Adapter in the coil. Large vials do not need an Adapter. See Section 4.4 for details.

With the vial or vials (and adapter) in place, loosen the coil gate handle a turn or two counterclockwise, align the handle with the slot, close the gate, and turn the handle clockwise until the gate is in snug contact with the vial or vials. To lock the gate, fold down the gate handle against the gate. Do not overtighten the gate, as this can crack the vial’s center

section.

If the Freezer/Mill tub is empty, pour liquid nitrogen (LN) into the tub about a third of the way. Initially LN will boil off vigorously, but as the tub cools the boiling will subside. Add more LN gradually, to avoid splashing and boiling over. When the LN is up to the fill mark and boiling is subdued, push the lid down gently until the bottom of the latch can be engaged; the lid is still not locked down. Pause if splashing becomes excessive. When the vapor stream has subsided, open the lid again and top off the liquid nitrogen in the tub, filling it to the mark on the inside wall of the tub. If you have not already done so, insert a loaded vial or vials in the coil, and tighten and lock the coil gate. One or two additional vials can also be put in the precooling chamber above the coil at this time.

Shut the Freezer/Mill’s lid, engage the latch as before, and lock the lid shut by pushing the top of the latch toward the lid. When the lid is closed and latched, further nitrogen boiling will be visible as a stream of condensed water vapor (“fog”) from the vent in the rear of the Freezer/Mill; this is normal. A grinding program can now be run, as outlined in Section 5.3, Status Screen.

6.2 Loading Samples into Freezer/Mill Vials

6.21 Introduction and General Recommendations

Pick a sample typical of those you will be grinding. As a rule of thumb, the sample should be in pieces small enough to circulate inside the vial as the impactor moves back and forth, and should take up no more than half the volume of the vial, with the impactor in the vial. These are typical

sample sizes for the different sizes of Freezer/Mill vials:
Sample	Large Vial	Mid-Size Vial	Small Vial	Microvial
Plant Tissue,	20-40 g	5-20 g	2-5 g	100-300 mg
Bone, Muscle, etc.
Polymer	10-20 g	2-10 g	1-2 g	50-100 mg
pellet.

In practice, the optimum parameters (sample weight and size, pre-cooling time, grinding times and number of cycles, impactor rate, etc.) are customized to match particular samples. Your own

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