100 ml · room-temperature storage (15–25°C) · both filter paper and swab methods validated per IFU Rev. 2023-12
QC organisms available from the same supplier.
For In Vitro Diagnostic Use Only | High Complexity | GHS Signal Word: DANGER
Nearly 100 years of established chemistry (Kovacs, 1928). CLSI M35-A2 aligned. Room-temperature storage. QC organisms from the same supplier.
Stores at 15–25°C — no refrigerated shipping, no cold-pack receiving, no refrigerator space required.
IFU Rev. 2023-12
Filter paper method (Whatman No. 1) and direct colony swab method — both validated in the IFU. Hardy Z67 is not validated for colony spot testing.
IFU Rev. 2023-12, Procedure
5 g of p-dimethylaminobenzaldehyde per 100 ml — the concentration specified in CLSI M35-A2 for spot indole testing.
CLSI M35-A2 + IFU Rev. 2023-12
IFU-specified QC organisms available from Pro-Lab Direct: PLD02 (E. coli ATCC 25922) and PLD04 (K. pneumoniae ATCC 13883).
IFU Rev. 2023-12, QC section
Select your role to see how PL.375 fits your specific workflow.
CLSI M35-A2 Aligned Indole Testing — Documented for High Complexity Microbiology Laboratories
When CAP comes through, your documentation needs to show CLSI-aligned methodology, IFU-referenced QC organisms, and traceable lot validation. PL.375 delivers all three — room-temperature storage, both filter paper and swab methods validated, and QC organisms (PLD02/PLD04) available directly from Pro-Lab Direct.
Q: We're validated on Remel R21227. Does switching require full revalidation?
The active chemistry is the same — p-DMAB at 5% w/v (isoamyl alcohol carrier, HCl). Lot-to-lot validation using PL.375 IFU-specified QC organisms (PLD02/PLD04, both available from Pro-Lab Direct) follows the same procedure as your current lot change protocol.
Spot Indole Testing That Works at the Bench — Filter Paper and Swab Methods, Both Validated
When you're running gram-negative workups, the indole test is as routine as the oxidase. You need a reagent that works the same way every time, doesn't require digging around the fridge, and gives you a clear red colour in under 3 minutes.
Q: What does an orange colour result mean?
Orange is a variable result — caused by skatole, a methylated precursor to indole. Repeat with a fresh colony. If the repeat is also orange, record as variable and proceed per your lab's SOP.
100 ml Room-Temperature Reagent — Larger Safety Stock, No Cold-Chain Receiving
Room-temperature storage at 15–25°C, a 100 ml bottle that provides significantly larger safety stock than competitor 15–25 ml bottles, and direct ordering from pro-lab-direct.com.
Organisms by indole test result — cherry-red colour within 3 minutes (positive) or no colour change (negative). Source: IFU Rev. 2023-12; standard clinical microbiology references.
Complete your gram-negative identification workflow with Pro-Lab products.
PLD02
IFU-specified positive QC organism for PL.375 lot validation — produces cherry-red colour with Kovacs' Reagent.
View ProductPLD04
IFU-specified negative QC organism for PL.375 lot validation — no colour change expected with Kovacs' Reagent.
View ProductPL.391-10
DMACA-based alternative — produces blue colour; also sanctioned by CLSI M35-A2 for spot indole testing.
View Product| Catalog Number | PL.375 |
|---|---|
| Volume | 100 ml |
| Storage Temperature | 15–25°C (room temperature — no refrigeration required) |
| Active Ingredient | p-Dimethylaminobenzaldehyde (p-DMAB), 5 g per 100 ml (5% w/v) |
| Carrier Solvent | 1-Pentanol (amyl alcohol); Hydrochloric acid |
| CLIA Complexity | High Complexity |
| Methods Validated | Filter paper method (Whatman No. 1); Direct colony swab method |
| Positive Result | Cherry-red colour within 3 minutes |
| Positive QC Organism | Escherichia coli ATCC 25922 (PLD02) |
| Negative QC Organism | Klebsiella pneumoniae ATCC 13883 (PLD04) |
| Controls Included | Not included — order PLD02 and PLD04 separately |
| Instrument Required | None |
| IFU Revision | 2023-12 (December 2023) |
| Regulatory Status | For In Vitro Diagnostic Use Only; CE IVD |
| GHS Signal Word | DANGER — H226 (Flammable), H314 (Corrosive), H332, H335 |
| Price (USD) | $65.27 — order direct from pro-lab-direct.com |
Side-by-side comparison based on published IFU data.
Source: PL.375 IFU Rev. 2023-12; Remel R21227 IFU; Hardy Diagnostics Z67 IFU. All comparisons based on manufacturer-published IFU documents.
No — PL.375 stores at room temperature, 15–25°C, until the expiry date on the label. No cold-chain shipping, cold-pack receiving, or refrigerator storage is required. Remel R21227 requires 2–8°C refrigeration — a meaningful logistics difference.
Yes — PL.375 validates both the filter paper method and the direct colony swab method in the IFU (Rev. 2023-12). Apply 1–2 drops to reagent-saturated filter paper or to a cotton swab tip; touch to colony; read within 3 minutes. Hardy Diagnostics Z67 explicitly states it is NOT for use in the filter paper spot test.
PL.375 contains 5 g of p-dimethylaminobenzaldehyde (p-DMAB) per 100 ml — a 5% w/v concentration. CLSI M35-A2 (Abbreviated Identification of Bacteria and Yeast) specifies 5% w/v p-DMAB as one of two sanctioned reagent formulations for the spot indole test.
High Complexity — consistent with standard biochemical identification tests performed in accredited clinical microbiology laboratories. Document this classification in your CLIA/CAP quality records.
The IFU (Rev. 2023-12) specifies E. coli NCTC 12241 / ATCC 25922 as the positive control (PLD02 — produces red colour) and Klebsiella pneumoniae NCTC 9633 / ATCC 13883 as the negative control (PLD04 — no colour change). Both QC organisms are available directly from Pro-Lab Direct — order them with your reagent in the same purchase order.
Orange is a variable result — typically caused by skatole, a methylated precursor to indole. Repeat the test using a fresh colony or a new culture. If the result is consistently orange, record as variable and proceed with supplementary identification per your lab's SOP.
No — glucose-containing media inhibit indole production and may cause false-negative results. Use non-glucose-containing media (blood agar, tryptic soy agar, or nutrient agar) for cultures to be tested with Kovacs' Reagent. This limitation is stated explicitly in IFU Rev. 2023-12.
Ships direct from Pro-Lab — same or next business day
Single bottles and small quantities — direct online ordering
Hospital systems, reference labs, and Net 30 accounts
15 minutes with a Pro-Lab microbiology specialist — IFU, validation documentation, or ordering questions
