# What platelet-rich plasma is and why it may differ *PRP therapy Tempe | What Platelet Rich Plasma Means* > Platelet rich plasma explained in plain words: how PRP comes from your blood, why preparations differ, and useful clinic questions. A sore knee may pinch during the first few steps from bed. It can ease by lunch, then ache again after errands. PRP may come up when simpler care hasn't helped enough. You can understand how the shot is made without a science lesson. ## How is platelet rich plasma made? The clinic takes a little blood from you. A machine spins it and separates a portion holding more platelets, which help blood clot. That portion is platelet rich plasma, usually shortened to PRP. Clinic staff give it as a shot into the sore joint or nearby tissue. **What's the simple answer?** The PRP comes from you, not a donor. It isn't surgery, and your visit still begins with an exam. ## Why isn't every PRP preparation the same? Clinics may draw different amounts of blood or keep different layers. Some PRP keeps white blood cells, while another mix removes most of them. Keeping more white cells may leave you sorer after the shot. It still doesn't prove that one blood mix will help you more. During a QC Kinetix visit, regenerative treatments means blood-based care given there without surgery. You can discuss PRP and how clinic staff make it. Medical providers are the staff doing your exam and giving care. They'll explain the mix and say when another choice may fit better. ## What is worth asking before you decide? Ask which joint or nearby tissue seems to cause your soreness. Then ask what daily movement might improve and when you'd notice a change. You'll need the full price and details about follow-up care. Written directions can explain activity limits and what to do with your medicines. PRP can't promise relief, whatever the blood mix shows. A good talk leaves you clear about possible help, limits, and your next step. ## Sources 1. The PAW classification was proposed because PRP preparation protocols 'vary widely between authors and are often not well documented in the literature, making results difficult to compare or replicate'. It sorts preparations by three variables: the absolute number of Platelets, the manner of Activation, and the presence or absence of White cells - the three levers that make two injections both called 'PRP' materially different products. DeLong JM, Russell RP, Mazzocca AD — [Platelet-rich plasma: the PAW classification system](https://pubmed.ncbi.nlm.nih.gov/22738751/). *Arthroscopy*, 2012. DOI: 10.1016/j.arthro.2012.04.148. 2. The DEPA classification was built because platelet and leukocyte counts alone do not describe an injection. Applied retrospectively to 20 published PRP preparations, the dose of injected platelets ranged from 0.21 billion to 5.43 billion - a 25-fold spread. No device recovered more than 90% of the platelets in the blood drawn, and most preparations were contaminated with red blood cells: only three of the devices reached a purity score corresponding to more than 90% platelets relative to red cells and leukocytes. Magalon J, Chateau AL, Bertrand B, et al. — [DEPA classification: a proposal for standardising PRP use and a retrospective application of available devices](https://pubmed.ncbi.nlm.nih.gov/27900152/). *BMJ Open Sport & Exercise Medicine*, 2016. DOI: 10.1136/bmjsem-2015-000060. 3. A systematic review that screened 876 studies and extracted standardised data from 33 commercially available PRP systems and protocols found that final product concentrations of platelets, white cells and growth factors varied widely between systems, as did the preparation protocols themselves. Platelet concentration correlated directly with the volume of blood drawn and with the centrifugal force of the device. The authors called the heterogeneity between separation systems something that 'must be resolved for proper study of this promising treatment'. Fadadu PP, Mazzola AJ, Hunter CW, et al. — [Review of concentration yields in commercially available platelet-rich plasma (PRP) systems: a call for PRP standardization](https://pubmed.ncbi.nlm.nih.gov/30992411/). *Regional Anesthesia and Pain Medicine*, 2019. DOI: 10.1136/rapm-2018-100356. 4. In a controlled laboratory study, blood from five healthy donors was processed through three commercial PRP systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, red-cell and TGF-beta1 concentrations did not differ significantly between systems, but white-cell counts and PDGF-alpha-beta, PDGF-beta-beta and VEGF concentrations differed significantly across all three. Cascade produced leukocyte-poor PRP while GPS III and Magellan produced leukocyte-rich PRP with correspondingly higher white cells and growth factors. Castillo TN, Pouliot MA, Kim HJ, et al. — [Comparison of growth factor and platelet concentration from commercial platelet-rich plasma separation systems](https://pubmed.ncbi.nlm.nih.gov/21051428/). *American Journal of Sports Medicine*, 2011. DOI: 10.1177/0363546510387517. 5. Three healthy adults each donated 181 mL of blood which was processed through four commercial PRP kits (GPS III, Smart-Prep2, Magellan, ACP). The three kits that draw from the buffy-coat layer produced platelet concentrations 3-6 times baseline and white-cell concentrations 3-6 times baseline; the one kit drawing from plasma produced platelet concentrations only 1.5 times baseline. The authors concluded that the lack of standardisation of PRP preparation has contributed, at least in part, to the varying clinical efficacy reported for PRP. Fitzpatrick J, Bulsara MK, McCrory PR, et al. — [Analysis of Platelet-Rich Plasma Extraction: Variations in Platelet and Blood Components Between 4 Common Commercial Kits](https://pubmed.ncbi.nlm.nih.gov/28210651/). *Orthopaedic Journal of Sports Medicine*, 2017. DOI: 10.1177/2325967116675272. 6. The devices used to spin PRP at the point of care are cleared by FDA as clinical centrifuges, product code JQC, a Class I device under 21 CFR 862.2050 - for example the Biomet GPS Platelet Separation Kit (K030555, cleared 2003) and the Harvest SmartPrep2 / SmartPrep Platelet Concentration System (K103340, cleared 2010). That clearance covers the equipment that separates blood. It is not an FDA approval of platelet-rich plasma as a treatment for osteoarthritis, tendinopathy or any other orthopedic condition, and copy must never blur the two. U.S. Food and Drug Administration (Center for Devices and Radiological Health) — [510(k) Premarket Notification database and Product Classification: JQC, Centrifuges (Micro, Ultra, Refrigerated) For Clinical Use, 21 CFR 862.2050](https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPCD/classification.cfm?ID=JQC). *FDA accessdata (CDRH device databases)*, 2003. ## Would a clinic visit help you decide? At 1100 S. Dobson Rd., Suite 210, QC Kinetix provides consultations about regenerative treatment options, non-surgical choices prepared from your blood. Its medical providers, meaning staff who examine you, can explain whether one could suit the sore area. Talk to the clinic team: --- Straight answers for a joint that hurts. Simple help with aching joints, PRP, warning signs, home care, and nearby QC Kinetix visits for Tempe residents. Plain guidance for Tempe residents living with a sore joint or tendon. This site is operated by the owners of the QC Kinetix Phoenix-area clinics, including the Chandler and Scottsdale locations described here, and the business can benefit when readers book a consultation. © 2026 Tempe PRP Field Notes. General health education, not personal medical advice; urgent symptoms need prompt assessment.