Cryopreservation has many advantages over routine chemical fixation. Two of these are the almost spontaneous arrest of biological activity and the retention of material that normally would be lost with chemical fixation and dehydration. In the current study 2 systems were evaluated. Hyaluronic acid (HA) was covalently bound to 1.4nm nanogold® and applied to astrocytoma cell cultures and the uptake monitored over time using both cryopreparative methods and conventional chemical fixation. The second system evaluated was the detection of liposomes containing CFTR covalently bound to 1.4nm gold in the airways of mice from a phenotype of an inbred congenic strain of CFTR-knockout mice that spontaneously develop lung disease.

In the HA uptake experiment, astrocytoma cell cultures were treated with HA gold for either 5, 10 or 20 minutes. At the appropriate time point, cells were either plunge frozen in liquid ethane or fixed with 2.5% glutaraldehyde in phosphate buffer.