8218–01 L Microplates, PS, Black — 290-8229-Z1L | 15/Box | Caplugs® Evergreen

384-Well Microplate Lids, PS, Black — 290-8229-Z1L | 15/Box (105/Case)

Technical Narrative

The Caplugs® Evergreen is a black PS 384-well microplate lid — the light-excluding evaporation control solution for 384-well fluorescence HTS and HTRF assay incubation. Unlike natural PS lids that allow ambient light to enter the plate during incubation, the black PS construction blocks light from reaching well contents — preventing the photodegradation of light-sensitive fluorescent reagents (fluorescent antibodies, HTRF acceptor dyes, fluorescent probes) that occurs with transparent lids during incubation steps under laboratory fluorescent or LED lighting.

For HTRF assays in particular, ambient light exposure during the compound-plus-antibody incubation step can quench the europium cryptate donor fluorescence that drives the time-resolved FRET signal. A black lid over a black plate provides complete light exclusion throughout the incubation period without requiring incubator light cutoff or foil plate wrapping. PS construction is autoclave-compatible for sterilization before cell-based 384-well assays requiring sterile plate coverage.

At $77.67 per Box of 15 — $0.7398 per lid — the delivers light-excluding 384-well coverage at per-lid economics for high-volume HTRF and fluorescence HTS programs. Pairs with the 290-8225-Z10 black 384-well plate for complete light exclusion from both plate and lid.

Technical Specifications — Caplugs® Evergreen

Black 384-Well Lid Workflow Compatibility —

The black PS lid combines evaporation control with ambient light exclusion for light-sensitive 384-well assay incubation:

Black lid pairs specifically with black 384-well plates (290-8225-Z10) for maximum light exclusion in fluorescence HTS. For transparent monitoring of well contents during incubation, use natural PS lid (290-8218-01L) instead.

Chemical Resistance — Polystyrene (PS)

PS resists standard aqueous assay reagents. Autoclave-compatible.

Laboratory Applications

The serves HTRF and TR-FRET HTS programs requiring light exclusion during fluorophore incubation; fluorescence intensity HTS programs protecting light-sensitive antibody and dye incubation steps; 384-well cell-based assay programs using calcein, Alamar Blue, or DAPI under CO2 incubator light exposure; and any 384-well workflow requiring combined evaporation control and ambient light exclusion during incubation.

U.S. Manufacturing, Quality & Institutional Procurement

Every Caplugs® Evergreen lot is precision-molded at our California manufacturing facility and subject to rigorous dimensional inspection and material purity verification. We supply reference laboratories, hospital systems, biotech firms, and federal procurement offices under institutional pricing programs with blanket-order support and same-day shipping on stocked inventory. Request a sample below to validate before committing to volume.

Frequently Asked Questions — Caplugs® Evergreen

Why use a black lid instead of a natural PS lid for 384-well fluorescence assays?

Natural PS lids are transparent — ambient laboratory light passes through them and into the plate wells during incubation. For light-sensitive fluorescent reagents (HTRF donor dyes, fluorescent antibodies, DAPI, calcein, Hoechst), this ambient light exposure can cause photobleaching and quenching during incubation, reducing signal and assay reproducibility. The black lid blocks ambient light from reaching well contents throughout the incubation period — the same reason black plates are used instead of natural plates for fluorescence assays.

Is the black lid autoclave-compatible for cell-based 384-well assays?

Yes. The is molded from PS and is autoclave-compatible at 121°C / 15 psi for sterilization before use in cell-based 384-well assays. Autoclave in a sealed pouch — allow to cool before placing on culture plates.

Should I use the black lid with the black plate, or can I use it with any 384-well plate?

The black lid fits any standard SBS 384-well plate — you can use it with black (290-8225-Z10), white (290-8221-W10), or natural (290-8217-010) 384-well plates. The light-blocking benefit is most relevant when used with black plates for complete light exclusion from all directions. Using a black lid on a white or natural plate still blocks light from above but does not prevent side-wall light entry in the plate body.