R0 Medium (RPMI Without Serum)

Dillon Corvino

Serum-free RPMI 1640 medium used for dilution of whole blood prior to Ficoll gradient separation, and for initial PBMC washes.
Published

September 18, 2026

Protocol ID: BUF-R0-MED Version: v1.1 Author: Dillon Corvino Date: September 18, 2026

Purpose

R0 medium is serum-free RPMI 1640 used for diluting whole blood prior to Ficoll separation and for washing PBMCs following gradient isolation. The absence of serum preserves the density characteristics of blood during layering and ensures optimal interface formation on Ficoll.

Linked protocols

  • HUM-BLD-PBMC-ISO

Working buffer composition

Component Final concentration Notes
RPMI 1640 100% Base medium
FCS 0% Serum-free formulation
Antibiotics 0% Add only if required for sterility
Note

This buffer is intentionally serum-free to avoid interference with Ficoll density gradient separation.

Preparation

A. Preparation of stock (if applicable)

Not applicable — prepared directly as the working buffer.

B. Preparation of working buffer

R0 medium consists of sterile RPMI 1640 with no serum or additional supplements.

Preparation of 500 mL R0

  1. Obtain 500 mL sterile-filtered RPMI 1640.
  2. Inspect for turbidity or colour change; discard if contamination is suspected.
  3. Label the bottle clearly as R0 (RPMI, no serum).
  4. Store protected from light.

Optional antibiotic supplementation

If required for sterility during slower workflows: - Add 5 mL Penicillin/Streptomycin (100x stock) → final 1% (v/v). (Not recommended unless protocol explicitly requires it.)

Storage and stability

  • Store at 4 °C, protected from light.
  • Stable for 4–6 weeks unopened; 2–4 weeks after opening if handled aseptically.
  • Do not freeze.

Reagent details

Reagent Supplier Cat. # Notes
RPMI 1640 Various — Sterile-filtered
Pen/Strep (optional) Various — Only if supplementation required

Safety (brief)

  • Handle RPMI using aseptic technique to avoid contamination.
  • Work in a biosafety cabinet when preparing aliquots or supplementing.
  • Dispose of expired or contaminated medium as biohazardous liquid waste.

Version history

Version Date Author Changes
v1.0 2025-11-21 Dillon Corvino Initial release of R0 medium file
v1.1 2026-09-18 Dillon Corvino Migrated to shared summary:/helper architecture (buffer/protocol redesign).