Steroid isolation , depending on context, is the isolation of chemical matter required for chemical structure elucidation, derivitzation or degradation chemistry, biological testing, and other research needs (generally milligrams to grams, but often more  or the isolation of "analytical quantities" of the substance of interest (where the focus is on identifying and quantifying the substance (for example, in biological tissue or fluid). The amount isolated depends on the analytical method, but is generally less than one microgram.  [ page needed ] The methods of isolation to achieve the two scales of product are distinct, but include extraction , precipitation, adsorption , chromatography , and crystallization . In both cases, the isolated substance is purified to chemical homogeneity; combined separation and analytical methods, such as LC-MS , are chosen to be "orthogonal"—achieving their separations based on distinct modes of interaction between substance and isolating matrix—to detect a single species in the pure sample. Structure determination refers to the methods to determine the chemical structure of an isolated pure steroid, using an evolving array of chemical and physical methods which have included NMR and small-molecule crystallography .  :10–19 Methods of analysis overlap both of the above areas, emphasizing analytical methods to determining if a steroid is present in a mixture and determining its quantity. 
WEST ORANGE, NJ—Seemingly knowing full well that the relatively small and light ball was not designed for someone of his size, sources confirmed Tuesday that 25-year-old Darren Foerstner tried using a pink 6-pound bowling ball for one frame, all to the incredible amusement of friends and onlookers at Eagle Rock Lanes bowling alley. “When Darren walked up to the lane holding that little pink ball, we were all thinking, ‘Wait a minute, that ball is meant for children,’ but then we realized what he was doing, and everyone just started cracking up,” said friend Kelly Lingard, adding that, as part of his lighthearted and exceptionally entertaining display, Foerstner demonstrated that his thumb and fingers were unable to fit into the smaller holes of the pink ball, forcing him to palm it with his entire hand. “He told us he borrowed the ball from a 5-year-old girl, which was hilarious in and of itself, but then when he actually bowled with it, he wound up accidentally throwing it a few feet into the air, so it crashed really hard onto the lane before bouncing a few times and rolling into the gutter. It was very, very funny.” The spectacle reportedly then reached a hysterical climax after Foerstner attempted to throw the pink ball through his legs and inadvertently tossed it onto the wrong lane, prompting fits of joyous laughter from everyone present as he quickly apologized to the adjacent group of bowlers.
The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine .