Separation of lymphocyte subsets by expanding velocity sedimentation of E-rosettes at unit gravity

Acoustic Cell Separation Based on Density and Mechanical Properties

Density and mechanical properties (e.g., compressibility or bulk modulus) are important cellular biophysical markers. As such, developing a method to separate cells directly based on these properties can benefit various applications including biological research, diagnosis, prognosis, and therapeutics. As a potential solution, surface acoustic wave (SAW)-based cell separation has demonstrated advantages in terms of biocompatibility and compact device size. However, most SAW-reliant cell separations are achieved using an entangled effect of density, various mechanical properties, and size. In this work, we demonstrate SAW-based separation of cells/particles based on their density and compressibility, irrespective of their sizes, by manipulating the acoustic properties of the fluidic medium. Using our platform, SAW-based separation is achieved by varying the dimensions of the microfluidic channels, the wavelengths of acoustic signals, and the properties of the fluid media. Our method was applied to separate paraformaldehyde-treated and fresh Hela cells based on differences in mechanical properties; a recovery rate of 85% for fixed cells was achieved. It was also applied to separate red blood cells (RBCs) and white blood cells (WBCs) which have different densities. A recovery rate of 80.5% for WBCs was achieved.

Localization of chicken parathyroid glands through vital staining

Five, fat-soluble dyes and one, metachromatic tissue dye were administered to White Leghorn hens and broilers to determine how these compounds would color parathyroid tissue for subsequent gland localization. Sudan black, sudan red, canthaxanthin, oil red O, beta-apo-8'-carotenal, and toluidine blue O were administered orally in gelatin capsules once a day for 1, 2, or 3 days before slaughter. The dyes were administered at approximately 100 mg/dose. The carotenoid pigments were given at 200 mg/dose. Two administrations were required to develop sufficient visible staining. All dyes except the toluidine blue O were visibly deposited in the parathyroid glands. Sudan black resulted in the greatest contrast with surrounding adipose tissue. Male broilers 3 wk of age that were given one dose of sudan black showed gland definition comparable to that seen in the hens after two doses. Male broilers 5 wk of age showed less gland definition when given sudan black or sudan red for 1 or 2 days. A histological examination indicated that the fat-soluble dyes were located extracellularly. These results indicate that sudan black can be used to visually identify the parathyroid glands of chickens.