The Terragene Bionova steam sterilization indicator reaches Thailand through BCST — giving hospitals, dental clinics, food production facilities, pharmaceutical manufacturers, and sterilization departments a validated, single-use biological indicator system for monitoring steam autoclave cycle efficacy. Two readout options cover every workflow: the BT220 for 3-hour fluorescence rapid readout, and the BT20 for 24-hour visual color-change readout using a standard incubator.

What Is A Steam Sterilization Indicator And Why It Matters

A sterilization cycle that looks correct is not the same as a sterilization cycle that performed correctly. Chemical indicators confirm that steam was present and that the package reached the required temperature zone. However, they do not confirm that sterilizing conditions were sufficient to eliminate the most resistant microorganisms within the load.

Only a biological indicator does that. Furthermore, biological indicators are the most direct, most sensitive, and most internationally recognized method for confirming sterilization cycle efficacy. Live, resistant spores serve as the challenge agent. If the spores die, the cycle worked. If they survive, the cycle failed. The result is unambiguous.

Regulatory standards, accreditation bodies, and infection prevention guidelines worldwide require sterilization monitoring at defined frequencies. In Thailand, hospitals, dental clinics, pharmaceutical manufacturers, and food production sterilization programmes all face biological indicator monitoring obligations. Consequently, a reliable, validated steam sterilization indicator is not optional — it is a compliance and patient safety requirement.

How To Choose The Right Readout Time

Select the variant that matches your incubation equipment and workflow. Both options use the same challenge organism — Geobacillus stearothermophilus ATCC® 7953 — against the same steam sterilization cycle parameters at 121–135°C.

3-Hour Fluorescence Rapid Readout — TER-BT220

For facilities with Terragene Bionova Auto-Reader Incubators requiring same-shift cycle release.

The BT220 steam sterilization indicator delivers a validated result in 3 hours through fluorescence detection. The Terragene Bionova Auto-Reader Incubator activates the spore carrier with UV light at an excitation wavelength of 340–380 nm and reads fluorescence emission at 455–465 nm. Fluorescence indicates viable spore growth — a sterilization failure. Absence of fluorescence at 3-hour incubation confirms a negative result — the cycle was successful.

This rapid readout transforms cycle release workflows. Additionally, a sterilization load processed and incubated at the start of a clinical shift delivers a confirmed result before the shift ends. Instruments do not wait 24 hours in quarantine before release. Therefore, patient throughput increases and sterile processing efficiency improves significantly.

Spore organism: Geobacillus stearothermophilus ATCC® 7953 Spore population: 10⁶ spores per vial Readout method: Fluorescence detection — Terragene Bionova Auto-Reader required Incubation: 60 ± 2°C, maximum 3 hours Process indicator: Label changes pink to brown confirming steam exposure Sterilization cycles: Vacuum-assisted and gravity displacement steam, 121–135°C Optional visual confirmation: 48 hours or 7 days at 60°C — purple medium indicates success, yellow or green indicates failure Storage: 15–30°C, 30–80% relative humidity, dark place Shelf life: 2 years SKU: TER-BT220

Important: The 3-hour fluorescence readout requires the Terragene Bionova Auto-Reader Incubator. Facilities without this equipment should select the BT20 24-hour variant, which operates with any standard incubator capable of maintaining 55–62°C.

24-Hour Standard Readout — TER-BT20

For facilities using standard incubators. No auto-reader required.

The BT20 steam sterilization indicator delivers a validated result in 24 hours through visual color-change detection. It operates with any standard laboratory incubator capable of maintaining 55–62°C. After sterilization, crushing the glass ampoule releases culture medium onto the spore carrier. The indicator then incubates at 55–62°C. Living spores produce metabolic activity that changes the medium to yellow — a clear sterilization failure signal. Successful sterilization leaves the medium unchanged.

The result is visible, clear, and requires no reader instrument. Furthermore, the BT20 uses the same challenge organism and meets the same steam cycle validation standard as the BT220. Therefore, laboratories without auto-reader infrastructure access the same level of biological indicator validation with equipment they already own.

Spore organism: Geobacillus stearothermophilus ATCC® 7953 Spore population: 10⁵ or 10⁶ spores per vial (per batch COA) Readout method: Visual color change — yellow indicates failure, no change indicates success Incubation temperature: 55–62°C (functional and required range) Maximum incubation: 24 hours D-value: Not lower than 1.5 minutes at 121°C (per COA) Z-value: Declared per batch COA Process indicator: Label changes to brown confirming steam exposure Sterilization cycles: Vacuum-assisted and gravity displacement steam, 121–135°C Storage: 10–30°C, 30–80% relative humidity, dark place Shelf life: 2 years SKU: TER-BT20

Step-By-Step Instructions — Both Variants

Step 1 — Label the SCBI tube with the sterilizer number, load number, and processing date before placing in the load.

Step 2 — Pack the biological indicator alongside the materials to be sterilized. Place it in the most inaccessible area — typically the center of the load and areas near the door.

Step 3 — Run the sterilization cycle as normal.

Step 4 — After the cycle completes, open the sterilizer door and wait five minutes. Then remove the SCBI. Wear safety glasses and gloves. Do not crush or excessively handle the SCBI — this may cause the glass ampoule to burst prematurely.

Step 5 — Allow the SCBI to cool to room temperature. Check the process indicator on the label. Brown coloring confirms steam exposure. If no color change occurs, investigate the sterilization process immediately before proceeding.

Step 6 — Crush the ampoule inside the tube using the ampoule crusher. Shake the tube vigorously until the culture medium reaches the base and fully soaks the spore carrier.

Step 7 — Incubation By Variant

For TER-BT220: Place immediately in the Terragene Bionova Auto-Reader Incubator at 60 ± 2°C. Read at 3 hours maximum.

For TER-BT20: Place in a standard incubator at 55–62°C. Read at convenient intervals. Final readout at 24 hours maximum.

Step 8 — Always incubate a non-sterilized SCBI from the same batch simultaneously as a positive control. Moreover, the positive control must show a positive result — confirming incubation conditions are correct, the medium supports growth, spore viability is intact, and equipment functions correctly.

Step 9 — Record all results. Do not use the sterilizer until the processed biological indicator result confirms negative. Positive results require immediate investigation of the sterilization process.

Disposal And Safety

Deactivate positive biological indicators before disposal. Autoclave at 121°C for at least 20 minutes in gravity displacement, at 132°C for 15 minutes, or at 134°C for 10 minutes in vacuum-assisted steam. Dispose of all biological indicators according to your facility’s biosafety regulations and applicable Thai national regulations.

Product Specifications

Compliance and Standards

Terragene Bionova biological indicators are manufactured in Rosario, Argentina under ISO 9001-certified quality management. Parameters are validated against USP and ISO 11138 standards for biological indicators — the international standard governing performance requirements for biological indicators used in sterilization. Terragene declares all D-values, Z-values, and spore population data per batch Certificate of Analysis. Contact BCST to request the COA for any Terragene product supplied.

Available in Thailand from BCST — Biochem Scitech Co., Ltd. Select your readout time from the dropdown above and contact BCST for pricing, volume requirements, and COA documentation.