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Penicillin Major (PPL)

Overview

Field Detail
Drug class Penicillin major determinant
Stock Pre-filled vial (Penicilloyl polylysine)
Reconstituted conc. 0.04 mg/20.00 mg per mL
Diluent 1 mL Saline in phosphate buffer
Storage 2–8°C

Preparation

Before you start

PPL is often supplied as a ready-to-use or minimally reconstituted kit. Check expiry and integrity.

Step 1 — Preparation

  1. Follow manufacturer instructions to reconstitute if necessary with the provided diluent.
  2. The standard RPAH testing concentration is 0.04 mg/20.00 mg per mL (Neat).

Step 2 — Prepare the SPT solution (Neat)

  1. Draw up 0.1–0.2 mL of the neat solution.
  2. Label: "PPL SPT (Neat)".

Step 3 — Prepare IDT dilutions

  1. IDT 1:10 (0.004 mg/2 mg per mL): Draw 0.1 mL of neat PPL into a 1 mL syringe. Add 0.9 mL of normal saline. Mix. Label: "PPL IDT 1:10".

Skin prick test (SPT)

Reagent Concentration
Test solution Neat (0.04/20.00 mg/mL)
Positive control Histamine 10 mg/mL
Negative control Normal saline

Interpretation: Wheal ≥3 mm vs negative control = positive.

Intradermal test (IDT)

Dilution series

Step Dilution Concentration Preparation
1 1:10 0.004/2 mg per mL 0.1 mL neat + 0.9 mL normal saline
2 Neat 0.04/20.00 mg per mL Undiluted

Inject: 0.05 mL intradermal. Read at 15–20 minutes.

Notes

  • Use phosphate-buffered saline as diluent — not plain normal saline.
  • Typically tested alongside Penicillin Minor (MD) and Amoxicillin as part of a full penicillin allergy workup.