Many of you might have wondered in the past: Where does your lab get samples from? You probably assume (correctly) that the normal procedure is to find a catalog, look up the thing you want to buy (for instance, DNA), and order it. A second method is to grow your sample, normally in bacteria, to get large amounts of sample.
For our nucleosome experiment, neither of these are practical or economical for the amounts that our group will use. So instead, we need to get nucleosomes from a source that has already done the work of making them. The preferred sources are from calf thymus (the thymus is an organ in front of the heart that is a vital part of the immune system) or chicken erythrocytes (chicken blood). I prefer the chicken blood as it is something easily collected, handled, and processed. (As an interesting side note, the blood could come from a non-mammal source. Mammal red blood cells do not have nuclei and therefore do not have significant quantities of DNA.)
Now I like to have approximately 200ml of chicken blood to create my samples. One option is to extract 1ml of blood from 200 chickens. With each chicken containing approximately 100ml of blood, they probably would barely know it. However, because it is much quicker (and as these chickens are going to be killed anyway), I prefer to collect all 100ml from each chicken.
This requires me to find a chicken butcher that allows me to collect blood from the slaughter. Normal slaughterhouses, with their incredible efficiency (for some disturbing pictures, try here) are not a viable option. So I need to find a small scale farmer that hand slaughters his or her chickens.
Rettland Farms, a wonderful local farm that sells free range (really free range, unlike most labeled as such) chickens. He pointed me to his processor over in Waynesboro, PA. To make a long story short, the processor is doing relief work in Haiti, will be out of the country until August, and has someone else filling in for him. I put in a call to the cellphone of his replacement slaughterer (pictured at right), a member of a Mennonite farm collective.
So to wrap it all up, I'm waiting for a Mennonite slaughterer to check his cell phone's voice mail and return my call so I can ask him if I can hold a beaker under his chickens as he ends their lives.
Somehow we didn't cover this part of science in grad school.