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Milked venoms are generally preferred for bioassays and toxin purification while dissected venom glands are typically used for the extraction of mRNA or DNA and other purposes.

Our spider milking procedures were developed, by us, for good yields of a clean venom, without contamination from regurgitate and hemolymph and without causing harm or discomfort to the spider. Spiders are anesthetized, positioned under a dissecting microscope with a suctioned tube pressed against the mouth to catch and remove regurgitate. A specially shaped capillary is used to catch both fangs and harvest the venom while the spider is stimulated with low AC voltage and current. Mortality is very low, even for fragile spiders, and most spiders can be milked several times at intervals or one to four weeks.

Similar precautions are used for milking tarantulas, though there are some difference and the scale is larger. Their venom is generally collected in flexible plastic tubes to protect the fangs, since these spiders tend to be much stronger.

There are probably some differences in the composition of artificially milked venoms obtained with electric stimulation and naturally expressed venoms, especially since spiders are more sophisticated and may have some control over the composition in addition to the volume of venom that they use during prey capture and defense (Kristensen, C. (2005) Comments on the natural expression and artificial extraction of venom gland components from spiders. Toxin Reviews 24(3) pp 257-270.). Unfortunately, it is much more difficult and less economical to harvest naturally expressed venom from most species.

Frozen Venom (FV)
These are typically clear, colorless and somewhat viscous fluids. Protein concentrations are generally about 10% w/v (0.1 milligram per microliter) and densities is generally about 1.1 milligrams per microliter.

Lyophilized (freeze-dried) Venom (LV)
Venoms are are aliquoted by volume (in microliters) before lyophilization and sold according to the initial volume. Almost all spider venoms dry to a white, powdery pellets that dissolve readily when brought back to their initial volume with water or physiological saline.
Weights are about 20% (w/v) of the initial volume (0.2 milligrams per microliter) and protein concentrations are about 50% of the weight or 10% w/v of the initial volume.
For instance, 5 microliters of venom will dry to about 1 milligrams of powder containing about 0.5 milligrams of protein.

Venom Apparatus (VA)
This is the entire venom apparatus, including the paired chelicerae (fangs and paturons) and glands from a spider. Venom apparatus dissection is an older technique, which is rarely used now but can be done on request.

Venom Gland Pair (VGP)
Venom glands are generally dissected to order, shortly before shipment, so they will be fresh and appropriate precautions are used.

Dissected venom glands are usually used for the extraction of mRNA so we typically use procedures intended to improve RNA yields and stability. For instance, yields may be improved by milking the spiders a few days before dissection to encourage new synthesis and the dissections are done rapidly to get the glands on to dry ice or into a preservative as soon as possible.

Other precautions may be used if the glands will be used for toxin extraction, typically to prevent contamination by digestive and other fluids that may degrade toxins or assays.

In general, dissection is simple and rapid, though there are some exceptions. Glands from most labidognath (typical) spiders can be obtained by pulling chelicerae from anesthetized spiders and the attached glands simply pop out.  Glands of orthognath spiders (e.g. tarantulas) are obtained by removing the inner or medial cuticle of the paturons of the chelicerae, which exposes the glands.

Frozen venom gland pairs (FVGP)

The glands are generally rinsed in a physiological saline and dabbed dry before freezing on dry ice. They are kept frozen on dry ice or in an ultra-low temperature freezer before shipping on dry ice, without any warming or thaws.

Lyophilized venom gland pairs (LVGP)

Frozen glands are freeze dried under vacuum.

Preserved venom gland pairs (PVGP)

The glands are placed in excess RNAlater (a RNA preservative from Ambion) immediately after dissection. These are generally stored in a refrigerator and shipped at ambient temperature.

Fixed glands

Glands for histology can be fixed and shipped in STF, a proprietary fixative from Streck (www.streck.com). These can be shipped without HazMat restrictions.

Other preparations

Many other preparations can be provided, including 'milked' regurgitate and hemolymph. Please inquire.

Spider Pharm can also supply live animals for those who prefer to do the dissections themselves.