Single-spin vs double-spin
The two centrifugation approaches to PRP preparation. Single-spin is faster with lower concentration; double-spin separates and re-concentrates platelets for higher yields at the cost of time and technique sensitivity.
Single-spin and double-spin name the two basic centrifugation strategies for preparing PRP. A single-spin protocol centrifuges whole blood once, separating red cells from plasma, and harvests the platelet-bearing layer directly. A double-spin protocol adds a second centrifugation: the first spin separates, the plasma is transferred, and the second spin packs platelets into a pellet that is resuspended in a smaller plasma volume. Both aim at the same target — platelets separated from red cells and concentrated into an injectable plasma volume — by different routes.
The trade is concentration against simplicity. One spin is faster, involves fewer transfers, and is harder to get wrong — but typically yields modest concentration factors, since platelets stay diluted in a larger plasma volume. Two spins can reach substantially higher concentrations and let the operator choose the final volume, at the cost of time, additional open handling steps in tube-based workflows, and sensitivity to technique — a sloppy transfer or a mishandled pellet loses precisely the platelets the second spin was for.
Neither approach is clinically proven superior for hair loss: trial protocols vary too widely for a clean comparison, and the unresolved dose–response question means a higher factor is a difference, not automatically an advantage. What is established is that the two approaches produce different products — so the choice defines the service, and switching between them mid-programme quietly changes what patients receive.
The operational decision weighs session volume, staff skill and kit design: many closed commercial kits embed one philosophy or the other, and following the validated instructions for the kit in use beats improvising a hybrid. Whichever is chosen, the professional obligations are identical — written spin parameters (force, time, temperature), training so that every operator produces the same product, and periodic platelet counts to confirm the protocol still delivers what it did when it was validated. Documenting which approach a programme uses, and since when, keeps before-and-after comparisons meaningful.
