O negative

how ruby red it is,
this blood
pulled by a syringe
out into small vials
to be spun and stared
into its strange
universe of microbes.
it surprises you,
the color.
deep and rich, a small
river of it
sails under the bridges
of your bones,
seeks to fill
the tributaries reaching
the far ends
of fingers, of toes.
and now a part of it,
this liquid captured
in glass
has left you. marked
with your name
on white tape.